PCIe and SATA Solid State Drive in addition to speed what difference?
Found it to you!
Now when it comes to SSDs, the player most talked about products, management should have turned to PCIe and SATA ssd specifications. After all, in the PCIe bus bandwidth Austrian aid, the maximum transmission speed of at least 1000MB / s jump to more than exceed 2000MB / s, is full SATA 6GB / s models several times. But apart from this great difference in speed, PCIe SSD also has the advantage that it? Let’s easy to understand way to explore it.
PCIe lane configuration flexibility, SSD whirlwind speed unlimited
The current minority support PCIe bus interface SSD, although the unit price relative to SATA models are a little high, blood players still have high interest, but a lot of people try to patrons. Its appeal than the maximum access speed, after all, the current mainstream SATA transmission interface, SATA-IO noted that real and effective bandwidth at 570MB / s up and down the spectrum, and it cannot feed today’s high-speed solid-state hard flash memory configuration dish.
In contrast PCIe bus interface based on the use of this combination of channels can be elastically positioned to provide nearly endless supply of transmission bandwidth, giving all kinds of high-speed device utilization. Such as PCIe 2.0 x1 theoretical bandwidth has 500MB / s, despite the small loss to SATA 6Gb / s, but the combined 4-channel available 2000MB / s. If upgraded to become the main force of PCIe 3.0, configure a channel that is 984.6MB / s, 4 single integration is achievable 3938.4MB / s of the spectrum.
As a result, even if the PCIe 2.0 x2 so called early specifications of PCIe SSDs, thanks to 1000MB / s theoretical transmission bandwidth, the maximum speed can be light and easy over 700MB / s. Of course, this is just a simple example, say that speed is not fierce storm. After all, bandwidth utilization lies in the SSD controller, and even with the flash memory and firmware tuning other components, the concept and previous SATA models are no different.SATA SSD is subject to the transmission interface available bandwidth factors difficult to break through the highest access speed 570MB / s, PCIe products can easily offer multiple speeds, and they have been listed as the focus of development.(Illustrations from the point of view from the left in order, is PCIe 3.0 x4, PCIe 2.0 x4, PCIe 2.0 x2, SATA 6 GB / s models)
PCIe is not only fast, but also to simplify the transmission infrastructure level
PCIe SSD either support AHCI or NVMe, in addition to having the PCIe bandwidth advantages, as well as where it is better than SATA? Old architecture is the delay (Latency). SSD controller itself, primarily of internal flash memory operation and maintenance, as well as through the PCIe bus outside the class or SATA interface with a computer system communication link. Differences based architecture dictates, signal transmission pathways pure PCIe products, or that must traverse nodes is relatively SATA device is more streamlined.
The support PCIe SSD PCIe interface card either, M.2 and so any form of communication with the system must be linked through the PCIe bus links to the chipset or processor built-in PCIe controller, through peer node as as streamlined. In contrast SATA interface models, and multi-core systems between the SATA disk controller that gap, signal transmission and control inevitably generate additional delay, there is generally visible difference in performance testing influence (such as motherboard chipsets native built and the other third-party controllers).
Short delay means fast response, but the price higher than a length
These are the system architecture theory, but delayed it exists thing generally less noticed, can show a gap of software testing can be extremely limited. Just our usual ULINK test platform, its comprehensive performance assessment test script contains the entry delay, it was able to snoop through the PCIe and SATA models the difference between. Representative group of products as shown below, we are on hand only in respect of existing test sample machine, so that we delay this profile of thing.
The obtained results may not tell the difference day Heights, but at least did not surprise or naught, showed PCIe SSD delay did slightly better than the SATA models. Wherein 2 PCIe product, it can be regarded as probably the read and write latency are less than 20us, and SATA models in the range of 20 ~ 30us. Among them, because conditions vary controllers, flash memory, etc., there are 2 products write latency is more than to read some.
▲ HyperX Predator PCIe SSD and M6e of PCIe products, and the remaining 3 are all SATA 6Gb
The delay test script program, for reading and writing each instruction sent 1,953,125, the results of instruction execution time mean to us (microseconds: millionths of a second) that the.Of course, men are able to feel that nothing different, is another interesting question. But for commercial high load I / O application environment, the short time delay the inevitable product more attractive, as to whether the player need to pinch pennies, perhaps have to meet this condition it deep pockets.
Testing platform requirements:
- Processor: Intel Core i7-4770K
- Motherboard: Asus Z97-PRO (Wi-Fi ac)
- Memory: Kingston HyperX Genesis PnP DDR3-1600 4GB x 2
- System disk: Kingston HyperX SSD 240GB
- Operating System: Windows 8.1, Window 10 Pro 64bit Home Version