How to install and update the drivers for the video card NVIDIA Step 1: Visit the website address of Nvidia here to download the latest driver
Step 2: In the NVIDIA Driver Downloads section, there are two options for users looking driver was hand searched (Option 1) and automatic search (Option 2). Here, Vnreview only recommend finding the driver manually for the 2nd way is fairly simple.
Under Option 1, the user selects complete the following information: >> Product Type: The type of video card, including GeForce, ION, Quadro, NVS, nForce, Tesla and Legacy. >> Product Series: Series specific graphics card. GeForce 600 Series example, nForce 9 Series,
>> Product: Name of the video card specific. Eg GeForce GTX 690, Quadro K5000M, >> Operating System: The operating system is used. >> Language: Language.
Below is a selection of Vnreview illustration:
select "Search" to do a search site. Step 3: Appears latest drivers, select Download button to download them.
Step 4: Once the download is complete, proceed with the installation by selecting the software. Guidelines appear choose location decompression software. Always select Desktop to find and easy to remove after the installation is complete. Select OK to proceed with unpacking.
Step 5: Appear table settings, select "Agree and Continue"
Step 6: Now there are two options for you, one is installed by NVIDIA recommended (Express), two are installed under your user needs (Custom). In our view, you should choose to install 2, may choose to omit the unnecessary or not supported on your device. Select Custom and click Next.
Step 7: Appearances are customized to your preference. For the ordinary computer does not support 3D, you can omit this option. Click Next to continue the installation.
Step 8:window appears indicating the currently installed driver.
Then select Restart Now to restart your computer. The installation process is complete.
You will see some small differences after installation and a new driver update. Good luck.
Instructions on how to enable WiFi on Windows 10, shared by other wireless devices or other users easily
You are using the internet and want to share your other devices such as tablets, phones. Or share be.Ban you can apply tips below to play wifi on Windows 10, without the help of any other software.
Step 1: Right-click on the Start button (or press Windows + X), choose Command Prompt (Admin)
Step 2: Command Prompt window opens, enter the command: "netsh wlan set mode = allow ssid = hostednetwork wifiname key = password" and press Enter - You copy and then right-click commands Command Prompt window to paste into it.
Step 3: see announcement time: creating successful wifi hotspot (not yet wifi, do the next step 4).
Step 4: Type in the command: "netsh wlan start hostednetwork" to play wifi, finish typing, press Enter (appearance notice khởi The hosted network that has wifi) - You copy and then right-click commands Command Prompt window to paste
To replay the wifi you use "netsh wlan start hostednetwork"
Check, check and Onboard discrete graphics on a computer, laptop
There are many ways to test your graphics card information on your computer, laptop or onboard the left, from the use of software to the tools available on Windows. Here we will summarize for you the way you can distinguish
Check, check and Onboard discrete graphics on a computer, laptop
EXAMINATION, OR CHECK discrete graphics ONBOARD COMPUTER, LAPTOP
Method 1: Use the command dxdiag in Windows
Step 1: From the Start menu, select Run, then type the command "dxdiag" and enter
Step 2: You move through the Display Card.
If the display type Intel (R) HD Graphics (as shown below) is a video card Onborad
If the display of ATI, AMD, NVIDIA ... (as shown below), it is discrete graphics
Option 2: Using software testing information
You can use the software to check as: Z ...... CPU, GPU-Z, or CPUID HWMonitor. With this article we use the software to test CPU Z, the same tracks you offline.
Download: CPU Z
Run the CPU Z will look like the image below. Then you move through the Graphics card.
If the display type Intel (R) HD Graphics (as shown below) is a video card Onborad
If the display of ATI, AMD, NVIDIA ... (as shown below), it is discrete graphics
In many ways you can know exactly what is that your computer is to use discrete graphics cards or Onborad, which use them for efficiency. In addition, you may refer to our article as experience purchasing a video card, or removing the onboard video card to use the card to leave
There was a time when computer cases were seen as nothing more than the housing for your PC. People were happy to boast about their new processor or graphics card, but the humble chassis rarely got a look in. Then things started to get interesting; cases got better, flashier and more functional. They evolved beyond mere protective outer shells and into an integral component that could complement what resided inside.
Today, the sheer number of cases available can be a bit overwhelming. To help you choose we’ve gathered impressions from our own reviews, those of other top sites and from owners' feedback, explaining what features make them stand above the rest. Here are the highest regarded cases in every category: best overall, Mini-ITX, micro ATX, HTPC, budget and top concept case.
Best Overall Case for Enthusiasts
Corsair Obsidian 900D
Great | Differentiating Features
No better case for water cooling setups, high-quality construction, supports two PSUs, supports up to fifteen 3.5”/2.5” combo drive bays, five radiator mounting points.
No fan controller, only two front USB 3.0 ports, expensive.
If you consider yourself an enthusiast when it comes to PC building, then nothing but the best will do. Here we have the absolute pinnacle of PC cases; where design, function and looks all come together to form the perfect chassis. Picking a winner here was no easy task, and in the end it was a choice between two Super-Towers: the Corsair Obsidian 900D and the Cooler Master Cosmos II. Ultimately, the title went to Corsair’s beautiful behemoth, and here’s why...
As soon as you set eyes on the Corsair Obsidian 900D you’ll be amazed by just how big it is. Weighing 41 pounds and measuring 27.2 inches in height means that not only is this case built like a small tank, but it can hold an incredible amount of hardware.
While the 900D may ship with nine 3.5”/2.5” combo drive bays, as opposed to the Cosmos II’s thirteen, there’s the option to purchase an extra three drive cages, bringing the total up to fifteen. There are also five 5.25” bays, one more than Cooler Master’s case. So whether you’re building the ultimate gaming machine or a beefy server, the Obsidian’s got you covered. Being a Super-Tower, this case can hold several varieties of motherboards, including E-ATX, XL-ATX and HPTX. Additionally, the 900D has room for two vertically mounted PSUs, whereas the Cosmos II has space for one.
The main chamber in this case is, as you would expect, cavernous, with the top section almost being the size of a standard full-tower. With its ten expansion slots and unbeatable cooling potential, you could put enough GPUs in here to make 4K gaming at 60fps an absolute breeze. And speaking of cooling, this is an area where the Obsidian truly excels; not only does it have fifteen fan mount locations (and comes with three 120mm and one 140mm fans), but there are also five radiator mounting points sized from 120mm up to 480mm. Add to this, the 900D lets you remove and rearrange everything with its tool-free design and you’ve got pretty much the perfect case for custom water cooling setups.
Some additional plus points for the Obsidian are its four easily removable dust filters, good airflow path, and the fantastic number of cable management options available, such as the cable routing latches and extra routing space behind the motherboard tray.
Does this case have any drawbacks? Well, there is the fact it has only two USB 3.0 ports, and the lack of a fan controller is a bit of a miss. The main problem people may find with the 900D is its eye-watering $300+ price, but this kind of quality doesn’t come cheap.
While no one can deny the Obsidian looks beautiful in a spartan yet bold kind of way, it may be one area where it plays second fiddle to the Cosmos II ($320). The 900D’s steel and cast aluminum frame, solid steel panels and full painted interior exudes quality, but the Cosmos’ elegant, race-car inspired design has the edge. Looks are, of course, a matter of personal taste. It could be said that visually comparing the Cosmos II to the 900D is like comparing a Ferrari to a luxury SUV.
While on the topic of alternatives, another consensus favorite among water cooling fans is the Phanteks Enthoo Primo ($250). The Primo is a well designed, well constructed chassis that can fit a ton of hardware but is less beastly than the 900D, which is part of the point. While a great case in its own right, it's worthy of mention here because of the raving user reviews and because it also costs less without skimping on build quality.
Make no mistake about it, both the Corsair 900D and the Cooler Master Cosmos II are stunning cases, both perfect for hardcore PC builders and gamers alike. But in the end, there can be only one winner. Because of its sheer number of build options and incredible flexibility the 900D takes the win, but only just.
Best Mini-ITX - Enthusiast/Gaming
Great | Differentiating Features
Beautifully sleek design, incredible easy to work on, innovative fanless design.
Good | Most Have It
Able to house GPUs up to 13 inches long.
Average | Competitors May Be Better
Lack of filters.
Although a full-sized tower PC case can look impressive, some people prefer the subtle elegance that comes with the Mini-ITX form factor. It used to be that these smaller cases couldn’t handle the more powerful components; today, however, Mini-ITX cases can house builds that will satisfy even the most hardcore gamers and PC enthusiasts. And the Silverstone Raven RVZ02 is the best of the bunch.
First thing you may notice about this case is that it looks more like a console than a PC, but despite its 12 liter capacity, the super-slim Raven can support dual slot GPUs up to 13 inches in length thanks to the use of a PCI-Express riser which is angled to position the graphics card parallel to the motherboard. This probably explains why the case is becoming a popular choice for Steam Machine builds, as does the inclusion of a slim optical drive bay.
One feature the Raven doesn’t have is any case fans. While this brave design choice may not give the most outstanding thermal performance, the oversized vents on the large transparent side/top panel allow the components within the Raven to blow out warm air using their own fan units – virtually replicating an open-chassis design.
Unlike a great number of Mini-ITX cases, the intelligent interior design of this case and tool-less drive cages mean that working inside this chassis doesn’t become a heart-pounding exercise in frustration. It’s even possible remove one component from the Raven without having to remove another component first - something not usually possible with cases of this size. There’s room for two 3.5” or 2.5” hard drives, and an additional drive can be installed depending on the length of the GPU.
The Raven RVZ02 is possibly the easiest Mini-ITX case you could work on. Its sleek looks and console-like profile mean it would be equally as comfortable beneath the living room TV as it would next to a monitor in the bedroom. Having no case fans means the Raven is lighter, cheaper to produce and has more internal space. And thanks to the intelligent airflow design, overheating isn’t a problem. Simply the best Mini-ITX case you can buy today.
Best HTPC case
Silverstone Milo ML04
Great | Differentiating Features
Great design, excellent price, easy to work on.
Good | Most Have It
Sleek A/V looks, can hold five 2.5" drives.
Average | Competitors May Be Better
Low profile expansion cards only, cable management can be an issue.
With a home theatre PC, you want something that can sit beneath (or next to) your living room TV and not look out of place. The best HTPCs shouldn’t look like computers; they should resemble a hi-tech piece of audio/visual equipment. Functionality, subtlety and style are some of the most important factors when deciding which home theatre case is the best of the bunch. Striking that perfect balance between looks and design is the SilverStone ML04.
The ML04 was created for the living room – and it shows. The excellent low-profile design and brushed aluminum front cover makes it appear much more expensive than its $80 - $90 price. It even comes with a lockable front door and power button, which not only adds a bit security but also contributes to the overall home theatre look. Additionally, at just 350mm deep and 105mm high, the Milo should fit inside all but the smallest of living room cabinets. Rounding off the outside of the case are two USB 3.0 ports, the audio input and the microphone jack.
Even with ML04’s small HTPC design, it can accommodate both Mini-ITX and Micro-ATX boards - giving builders a lot more options when it comes to choosing a mobo. There’s ample storage room in this case; it boasts a 5.25” bay that can also hold one 3.5” drive or two 2.5” drives, two more bays that can hold both sizes of drive, and finally a bay that can only hold only one 2.5” drive. This means the Milo ML04 can support a total of five 2.5” drives or three 3.5” drives. And with the huge capacity available on HDDs and SDDs today, you’ll have no trouble storing your entire media library inside this case.
Cooling can sometimes be an issue with HTPCs, but the ML04 makes good use of what little interior room it has. There are four 80mm fan slots (although no fans are included in the price, sadly) and some oversized vents above the CPU and on the side of the case.
Setting up the ML04, you can understand why it’s a favorite amongst those who regularly build HTPC systems. The only issue you’re likely to encounter is with cable management, especially if you use all five of those 2.5” drive slots. The size also limits the expansion cards to the low-profile variety, but you’re unlikely to want to play the Witcher 3 on your dedicated HTPC... or you could always use a riser and install a full size single-slot card above the motherboard, but that would limit the height of the CPU cooler.
With its great price, sleek looks and excellent design, the Silverstone ML04 is our top pick for anyone wanting to build a top quality entertainment center.
However, if the ML04 is just too small for you, and you’re the kind of person who prefers a big HTPC that can hold a similar amount of hardware as a tower case, then another one of SilverStone’s offerings, the Grandia GD08, will be a better option. While this case still retains the look of something that belongs in the living room, it has room for motherboards up to E-ATX in size, GPUs as long as 13.6 inches, twelve drive bays, and four 120mm fans.
Best micro ATX Cube
BitFenix Phenom mATX
Great | Differentiating Features
Can easily handle dual GPU setups, beautiful and solid construction, five motherboard expansion slots, space for ten hard drives.
Good | Most Have It
Comes with two 120mm fans, can fit a full-size ATX PSU.
Average | Competitors May Be Better
Cable management can be problematic. All expansion slots held in place by a single screw.
Micro-ATX cubes provide a good middle ground between a full-size case and a tiny mini-ITX chassis. Many can handle almost anything you care to throw into them, including more than one GPU and water cooling setups. From a wide range of excellent contenders, it’s the BitFenix Phenom mATX that comes out on top.
One of the first things you’ll notice about this case is just how roomy the interior is. With its five expansion slots, installing dual graphics cards (reaching 320mm in length) won’t feel like you’re playing a game of Tetris.
When it comes to keeping your components cool, you won’t find many other Micro-ATX cases that can accommodate water cooling setups as well as the Phenom. The case has room for a 240mm radiator or a CPU cooler up to 160mm in height. There’s also space for up to five fans across the top (120mm), bottom (120mm/200mm/230mm) and rear (120mm/140mm) of the case. The Phenom also comes with two 120mm fans as standard.
The Phenom has the added bonus of being able to fit a full-size ATX PSU along with five 3.5” and five 2.5” bays, meaning you’re unlikely to run out of room to add storage anytime soon.
Aesthetically, we find the Phenom to be beautiful with its flowing and minimalistic design, while the smooth edges and solid construction makes the case look more expensive than its sub-$100 price might suggest. Plus, it comes in black or white, so you can match it to your décor.
The only big drawbacks to this case are the messy cable management -- though that's usually hard to overcome in micro ATX cases -- and the way the expansion slots are held in place with a single screw. These are annoyances that may draw away some builders to go with something easier instead, but ultimately don’t detract from the overall quality of BitFenix's chassis.
As mentioned previously, there were a wide range of contenders in the micro-ATX cube category, and some came very close to overtaking the BitFenix as our favourite. One of the best alternatives to the Phenom mATX is Fractal Design’s Node 804 ($125). This case has a clean, minimalistic design and is capable of housing a beast of a gaming PC – it’s rare to find a micro-ATX cube that can support multiple radiators, ten storage devices and ten fans.
Another great case in this category comes from the always excellent Corsair, this time in the shape of the Carbide Air 240 ($115). This competitively priced, sturdy and compact chassis can hold radiators up to 240mm, has space for up to six storage drives, and - as its name suggests - is designed with optimal airflow in mind. It also has some fantastic cable management features for a smaller case, and a huge side window to show off your skills.
- The network cable (length according to your demand)
Currently there are two cable standards T568A click connect 2 computers together and T568B hub connecting two computers with cable press standards include:
- Press Straight: This type is used to connect two devices together kind. Example: PC + Switch, Switch + Router
RJ-45 JACK TIA / EIA 568A Standard called Standard A.
T568A: 1. White 2. Green 3. Green 4. Blue 5. Orange White White White Blue 6. Orange 7. Brown 8. Brown
- Press the Cross: This type is used to connect two devices of the same type together. Example: PC-PC, PC-Router ...
RJ-45 JACK TIA / EIA 568B standard STANDARD called B.
T568B: 1. 2. Orange 3. White Orange White Green Blue 4. White 5. Blue 6. Green 7. White-brown 8. Brown.
INSTRUCTIONS FOR CUTTING WIRES COMPUTER NETWORK
Cross-cutting cables
Step 1: You use pliers or scissors to cut the cable casing: about 4 cm
Step 2 : Remove the head and twisted in order: White prearranged - Orange - Blue - Green - Brown.
Step 3 : Change the white spot of white, green and blue of each other.
Step 4 Put the wires back together and using pliers to cut close to equal.
Step 5 : Your conduct wire inserted into the deep end of the cable to the wire touches the copper core.
Step 6 : then inserted into alkaline and press hard
Cable Straight Way Press
- Cut the cable cover and place the order wire 1 -> 2 -> 3 -> 5 -> 6 -> 4 -> 7 -> 8.
- Ratings by police again and cut back just enough not to 1 segment with RJ45.
Then the remaining steps do similar press crossover cable.
How to Share Files Between PCs, Smartphones and Tablets
When it comes to sharing files these days, it’s no longer just about sharingbetween computers. Now your friend with an Android phone might want some videos you took from your iPhone or you may want to copy a bunch of pictures from a Windows PC to your iPad.
In this article, I hope to give you as complete a guide to sharing across devices as possible. It’s going to be long, so feel free to skip down to the section that applies to you. The sections will be broken down into sharing between computers, sharing between computers and mobile devices, and sharing between mobile devices only.
When it comes to sharing files between computers, you can break it down into two types: local sharing or remote sharing. If you need to copy some files to another computer on your local network, it will be much faster because you’ll either be using Ethernet or Wi-Fi to perform the transfer.
This is the best way to transfer a large amount of data to another computer quickly. When copying files outside of your LAN (local area network), you are limited by your Internet speed. If you have Verizon FIOS with a 75 Mbps upload/download connection (which I have now), then transferring large amounts of data to a remote computer will also be fast.
However, if you’re stuck with AT&T and have a miserable 1.5 Mbps upload speed (which I had in the past), it’ll take a long time to upload a few gigabytes of data. Let’s first talk about local data transfers.
Instructions on how to split, merge and create drives on Windows 7/8 / 8.1 / 10 simplest.
How to split, join, create a very simple drive does not require software support.
When buying new computers, the default drive will certainly not make you happy. You can share the drive with guided discretion here without any software support. Tips apply to Windows 7 or newer.
Instructions on how to split, merge and create drives on Windows 7/8 / 8.1 / 10 simplest
Testing mobile G-Sync with the Asus G751JY: Boutique gaming’s killer feature?
Last January, we previewed how mobile G-Sync might perform on an Asus G751JY laptop that wasn’t fully certified for the feature but supported it well enough to give us a taste of what G-Sync could deliver. Today, we’re revisiting the topic, armed with a fully certified Asus G751JY-DB72. This system is nearly identical to the G751JY that we tested earlier this year, but with a handful of upgrades. Specifically, the G751JY-DB72 uses a Core i7-4720HQ CPU, 24GB of DDR3, a 256GB SSD, and a backup 1TB HDD for conventional mass storage. The system still uses a GTX 980M (4GB of RAM) and a 1,920-by-1,080, 17.3-inch screen.
At $1999 from Asus, it’s not a cheap laptop, but it’s one of the nicest and best-balanced systems I’ve ever tested. Because mobile G-Sync is a big enough feature to warrant its own treatment, we’re going to discuss the laptop’s performance and capabilities in a separate piece. For now, it’s enough to say that this is one of the best boutique laptops I’ve ever tested, even if the base model debuted a year ago.
How mobile G-Sync works
Mobile and desktop G-Sync accomplish the same goal, but they achieve it in different ways. Nvidia’s desktop G-Sync displays rely on a separate, Nvidia-built scaler unit. This scaler controls the monitor’s timing and synchronizes the display’s output with the video card. In 2013, when Nvidia debuted G-Sync, its custom scaler technology was the only way to achieve this kind of synchronization in a desktop display. That’s since changed with the launch of the VESA-backed Adaptive Sync standard (AMD calls its own implementation FreeSync). Laptops, however, don’t require custom scaler hardware — the ability to synchronize refresh rates is part of the embedded DisplayPort specification that both AMD and Nvidia use.
As the name implies, variable overdrive allows the display to decrease pixel ghosting by anticipating what color a pixel may need to be on the next refresh cycle and adjusting voltage accordingly. Nvidia has noted that this could result in a slight decrease in color accuracy in some conditions, but the net result should still be improved color reproduction.
G-Sync: A Goldilocks solution:
Now that we’ve covered the basics of how mobile G-Sync works, let’s talk about its specific implementation in the Asus G751JY. This laptop uses a 75Hz panel, which is important to know, because it specifies the maximum refresh speed at which G-Sync can operate. If you have a 75Hz panel and your game is kicking out a steady 200 FPS, G-Sync disables automatically and the game will switch to either V-Sync on or off. By default, NV switches to V-Sync on, since this is much less jarring then the sudden appearance of tearing, but if you prefer to disable V-Sync when the frame rate exceeds 75 FPS, you can specify that at the control panel.
This might seem less-then ideal, since gamers are typically taught to prefer high frame rates, but the relative advantage of faster FPS is subject to diminishing marginal returns. The higher the frame rate, the less visible a missed frame is.
If the frame rate falls below a certain level, however, G-Sync can run into another problem. While it doesn’t shut off due to low FPS, the GPU will automatically interpolate and insert multiple frames to smooth playback. If performance is relatively steady, this is an excellent way to smooth the game without impacting playability. If the frame rate is changing significantly from moment to moment, however, some frames will end up repeated and some will not.
PC Perspective wrote an excellent report on how FreeSync and G-Sync handle low frame rates. The graph below shows how G-Sync inserts additional frames, boosting the refresh rate as a result.
As the frame rate fluctuates, the number of frames G-Sync injects to smooth presentation can vary as well. While the end result can still be superior to not having G-Sync on at all, a variable frame rate below ~35 FPS doesn’t produce the buttery smoothness that Adaptive Sync and G-Sync provide at higher refresh rates.
This ideal window is why we call G-Sync (and Adaptive Sync) a Goldilocks solution. Both technologies work best when your frame rate is neither too high nor too low. In this case, users should target an average consistent frame rate between 40 and 60 FPS.
We first heard that Qualcomm was planning to enter the server market more than a year ago, but the company has been quiet about its intentions and roadmaps since that first announcement. Now that the curtain has lifted, we can see why the company wanted to keep things hush-hush. Unlike other ARM firms, which have entered the market with relatively modest chips or attempted to focus on specific market segments like high-density servers, Qualcomm is pulling out the big guns. The company’s new ARM server CPU is a vigintiquattuor-core (read: 24-core) chip.
Here’s the real kicker — that 24-core version is just a prototype. The final variant is expected to pack even more CPUs per core. PCIe and storage controllers are all integrated on-die, but Qualcomm isn’t giving out information on the architecture yet — just that it’s markedly different from the existing Snapdragon processor. The chip’s supposed codename is Hydra, and it’s been reported that Qualcomm could roll up to 64 cores into a single stack, though we don’t have confirmation of that yet.
Based on the size of the current CPU (as shown above), we’d bet that any future 64-core variant would be introduced at a smaller processing node. That’s a huge piece of silicon, and while Qualcomm’s CPUs might be smaller than Intel’s on a per-core basis, 24 cores is still a lot to pack into a single chip. When Intel designs its highest-end Xeon processors, it spends a great deal of time laying out the internal linkages and L3 cache to ensure that all of the cores have equal latency and that cache contention and thrashing are kept to a minimum. We don’t know how much cache Qualcomm has dedicated or much at all about the internals of this new core, but the fact that they’re committing to hardware on this scale means they want to compete for heavy-hitter business. Think Google, Facebook, and other top-end customers.
At Qualcomm’s demo, the company showed its new core running LAMP — Linux, Apache Web server, MySQL, and PHP, along with OpenStack’s cloud software. PCWorld reports that Mellanox is designing network cards for the SoC, while Xilinx is building FPGAs that will accelerate particular workloads.
Can Qualcomm win this fight?
Qualcomm is far from the only company moving in the ARM processor space, but it’s easily the biggest potential threat to Intel. The other companies in this market — Cavium, Broadcom, AppliedMicro, AMD, and several others — have products that range from niche applications to nonexistent (at least, in shipping commercial volumes). Qualcomm, of course, hasn’t shipped anything either, but it’s absolutely got the cash to bring hardware to market.
Of course, there are counters to this view, including the fact that Intel’s much-vaunted process engineering advantage is being threatened for the first time in over a decade. TSMC and presumably Samsung are known to have superior cost structures to Intel, which is why Chipzilla had to ship Atom contra-revenue in the first place. There’s definitely opportunity for ARM hardware overall, but the shape and size of that market are hotly contested, and Intel isn’t going to sit idly by and watch a competitor eat its most valuable market.
Here at ExtremeTech, we’ve often discussed the difference between different types of NAND structures — vertical NAND versus planar, or multi-level cell (MLC) versus triple-level cells (TLC). What we haven’t done is sit down and talk about the more basic relevant question: How do SSDs work in the first place?
To understand how and why SSDs are different from spinning discs, we need to talk a little bit about hard drives. A hard drive stores data on a series of spinning magnetic disks, called platters. There’s an actuator arm with read/write heads attached to it. This arm positions the read-write heads over the correct area of the drive to read or write information.
Because the drive heads must align over an area of the disk in order to read or write data (and the disk is constantly spinning), there’s a non-zero wait time before data can be accessed. The drive may need to read from multiple locations in order to launch a program or load a file, which means it may have to wait for the platters to spin into the proper position multiple times before it can complete the command. If a drive is asleep or in a low-power state, it can take several seconds more for the disk to spin up to full power and begin operating.
From the very beginning, it was clear that hard drives couldn’t possibly match the speeds at which CPUs could operate. Latency in HDDs is measured in milliseconds, compared with nanoseconds for your typical CPU. One millisecond is 1,000,000 nanoseconds, and it typically takes a hard drive 10-15 milliseconds to find data on the drive and begin reading it. The hard drive industry introduced smaller platters, on-disk memory caches, and faster spindle speeds to counteract this trend, but there’s only so fast that drives can spin. Western Digital’s 10,000 RPM VelociRaptor family is the fastest set of drives ever b
uilt for the consumer market, while some enterprise drives spun up to 15,000 RPM. The problem is, even the fastest spinning drive with the largest caches and smallest platters are still achingly slow as far as your CPU is concerned.
How SSDs are different
“If I had asked people what they wanted, they would have said faster horses.” — Henry Ford
Solid-state drives are called that specifically because they don’t rely on moving parts or spinning disks. Instead, data is saved to a pool of NAND flash. NAND itself is made up of what are called floating gate transistors. Unlike the transistor designs used in DRAM, which must be refreshed multiple times per second, NAND flash is designed to retain its charge state even when not powered up. This makes NAND a type of non-volatile memory.
The diagram above shows a simple flash cell design. Electrons are stored in the floating gate, which then reads as charged “0” or not-charged “1.” Yes, in NAND flash, a 0 means that data is stored in a cell — it’s the opposite of how we typically think of a zero or one. NAND flash is organized in a grid. The entire grid layout is referred to as a block, while the individual rows that make up the grid are called a page. Common page sizes are 2K, 4K, 8K, or 16K, with 128 to 256 pages per block. Block size therefore typically varies between 256KB and 4MB.
One advantage of this system should be immediately obvious. Because SSDs have no moving parts, they can operate at speeds far above those of a typical HDD. The following chart shows the access latency for typical storage mediums given in microseconds. extremetech
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