Performance Comparison between IDE and AHCI in Corsair Force Series 3 60GB SSD
So today I am going to show you the performance differences between IDE and AHCI mode in my Corsair Force 3 60GB SSD. Now most of us already are aware of what is IDE but what the heck is AHCI? What advantage could be gain from AHCI? Is AHCI is future thing of good old IDE interface. Will it slow down my system? Will it conflict my system?
AHCI & IDE SATA-Mode Differences
Most desktop computer motherboards offers hardware enthusiasts the option to adjust the SATA controller interface settings in their BIOS between AHCI and IDE mode. Traditionally, IDE is the time-tested standard for desktop hard drive products. The IDE interface offers basic control over the storage device, but unfortunately it does not include enterprise-level features. Advanced Host Controller Interface (AHCI) on the other hand, was created as a means to deliver additional storage support for server backplanes and high-end performance desktop computers.
AHCI is a hardware mechanism that allows software to communicate with Serial ATA (SATA) devices (such as host bus adapters) that are designed to offer features such as hot-plugging and native command queuing (NCQ),
that is not available in IDE mode IDE does not support RAID arrays, and does not include the extended power management features that AHCI offers. For OpenBSD servers, port multiplier support is also enabled through AHCI.
Many SATA controllers can enable AHCI either separately or in conjunction with RAID support. Intel recommends choosing RAID mode on their motherboards (which also enables AHCI) rather than the plain AHCI/SATA mode for maximum flexibility, due to the issues caused when the mode is switched once an operating system has already been installed.
AHCI is fully supported out of the box for Microsoft Windows 7 and the Linux operating system from kernel 2.6.19. NetBSD also supports drivers in AHCI mode out of the box in certain versions. Older operating systems require drivers written by the host bus adapter vendor in order to support AHCI.
Bandwidth Speed vs Operational Performance
The argument between AHCI and IDE SATA-modes revolves around two other dynamics: bandwidth speed (MB/s) and operational performance (IOPS). The two metrics work together, but one is more important than the other. Consider this analogy: operational IOPS performance determines how much cargo a ship can transport in one voyage, and the bandwidth speed is to fast the ship moves. By understanding this and applying it to SSD storage, there is a clear importance set on each variable depending on the task at hand.
For casual users, especially those with laptop or desktop computers that have been upgraded to use an SSD, the naturally quick response time is enough to automatically improve the user experience. Bandwidth speed is important, but only to the extent that operational performance meets the minimum needs of the system. If an SSD has a very high bandwidth speed but a low operational performance, it will take longer to load applications and boot the computer into Windows than if the SSD offered a higher IOPS performance.
Advantage of AHCI
1. Hot-Plugging (will not cover here as it will not affect computer performance)
2. Native Command Queuing (might improve computer/system/hard disk responsiveness, espcially in multi-tasking environment
Will it slow down my computer?
Several websites claim, NCQ (one of AHCI component) will cause performance degradation in single threaded benchmark, but other author claim otherwise. Let put our think hat here.
Their claims might correct at certain extent, but it is hard to prove that those single threaded benchmark will reflect real world application. Nowadays, hard disk is the slowest component in any modern PC (except we are using SSD). Antivirus, firewall, anti-spyware, windows update, background defragmentation, indexing (search), user applications (firefox, word, media player) ; all contribute to super multi-tasking, which I believe NCQ (AHCI) will show it advantage. So, in order to have better understanding on how NCQ (AHCI) could improve system responsiveness, let see what is NCQ actually is.
So, what is NCQ?:
In principle, Native Command Queuing is relatively simple. It allows the drive to execute write /read commands that are transmitted randomly in order to optimise the movement of the reading head.
Speed is increased but there is also an impact on power consumption and noise level which is reduced. Of course, applications don’t have to work simultaneously and don’t have to wait for the previous result to send the next command. This of course isn’t always possible. Another possibility in using NCQ is multitasking in the case where you run two very heavy applications simultaneously from the drive point of view.
To better explain this situation, imagine an elevator, in which two people enter simultaneously on the ground floor. The first pushes the 12th floor button and the second the 2nd floor. It would be counterproductive to go to the 12th floor and then to the 2nd floor. The principle of NCQ was already in the ATA norm since 1997 with TCQ (Tagged Command Queuing). This heavier protocol could sometimes lead to significant performance losses in the case of low loads (no or very little command reorganisation to do) and has been integrated in a limited number of controllers. Hitachi supports it on 7K250 drives, like Western and the Raptor WD740GD, while on the chipset side, we can count on NVIDIA but not Intel.
SATA 3.0 Gbits /s defines a new speed of data transmission for the Serial ATA interface. Initially, SATA reached up to 1.5 Gbits /s, which really corresponds to 150 mega-octets per second as 20% of information is dedicated to error correction. The transfer rate is now increased to 300 MB/s but we have to keep in mind that this is the interface speed. It has nothing to do with disc speed alone. At most, cache speed would be affected.
For NCQ to be enabled, it must be supported and turned on in the SATA host bus adapter and in the hard drive itself. The appropriate driver must be loaded into the operating system to enable NCQ on the host bus adapter. Many newer chipsets support the Advanced Host Controller Interface (AHCI), which should allow a generic driver supplied by the operating system to control them and enable NCQ. In fact, newer mainstream Linux kernels support AHCI natively. Unfortunately, Windows XP requires the installation of a vendor-specific driver even if AHCI is present on the host bus adapter. Windows Vista corrects this situation by including a generic AHCI driver.
Benchmark Time J
SSD Test Methodology
(+) means higher is better, (-) means lower is better
Processor: AMD Phenom II x6 1090T
Motherboard: MSI 890GXM-G65
Memory: G.skill Sniper 8GB DDR3 1866MHz
SATA 6Gb/s Storage HBA: AMD SB850 Rev 40
Hard Drive(s): Corsair Force Series 3 60GB SSD
Power Supply: Corsair 650TXV2
Operating System: Windows 7 Ultimate 64-bit
Read and or Write
HD Tune (IOPS)
Benchmark (HD Tune) HD Tune is a single-threaded applicationbenchmark used to calculate Transfer times, Access times, Burst Rate and CPU Usage of a hard drive. You can download HD Tune at www.hdtune.com. There are two versions of HD Tune, a pro and a free version (Pro Version does benchmark write speeds). The Pro version was used for this review.
IDE vs AHCI:
HD Tune Benchmark Summary
Using HD-Tune Benchmark the reported performance gain favored AHCI, Reported AHCI performance increase against IDE is 6-40% IOPS and avg. speed while 1MB transfer size remains almost same.
SATA Mode Recommendation: AHCI
Benchmark (AIDA64) AIDA64 is a diagnostic and benchmarking tool. AIDA64 will be used for its Disk Benchmark. We will use the read test suite.FinalWire is the producer of this software.
IDE vs AHCI:
AIDA64 Benchmark Summary
Using AIDA64 Benchmark the reported performance gain favored AHCI, Reported AHCI performance increase against IDE is 18-40% Read Suite while Average Read Access time is decreased by 0.1 ms. SATA Mode Recommendation: AHCI
Benchmark (ATTO) ATTO is a Hard Disk benchmark that that calculates both read and write times. You can download ATTO here.
IDE vs AHCI:
ATTO Benchmark Summary
Using ATTO Benchmark the reported performance gain favored both AHCI and IDE, Reported AHCI performance increase against IDE is in Read Speed by a good margin and Write speed is slightly reduced. SATA Mode Recommendation: AHCI
Benchmark (Crystal Mark) Crystal Mark is a disk benchmark software that features:
Using Crystal Mark Benchmark the reported performance gain favored AHCI, Reported AHCI performance increase against IDE is
38%+ in Seq
30%+ in 512K
10%+ in 4K
130%+ in 4K QD32 Over all performance increase is 52%+ and
Write Speed 8%+ in Seq 6%+ in 512K
28%+ in 4K
100%+ in 4K QD32Over all performance increase is 36%+
SATA Mode Recommendation: AHCI
Benchmark (AS SSD) The AS SSD benchmark by Alex Intelligent Software is specifically written for SSD drive performance measurements. AS SSD measures sequential read and write, access time and 4K IOPS both single threaded and 64-threaded. The official download can be found athttp://www.alex-is.de/PHP/fusion/dow....php?cat_id=4.
IDE vs AHCI:
AS SSD Benchmark Summary
Using AS SSD Benchmark the reported performance gain favored both AHCI and IDE, Reported AHCI Overall performance increase against IDE is same. Performance increased in Read Speed but reduced in Write speed SATA Mode Recommendation: Neutral
Benchmark (IOmeter) As the name implies, IOmeter is a benchmark utility for the I/O subsystem which is currently maintained and developed by Open Source Development Lab. IOmeter is set to use 4kb chunks with a queue depth of 32 I/O operations equally divided between read and write. Measurement is given in total IOPS in a two minute period. This particular script does not necessarily emulate real world conditions and has been known to favor the SandForce controller based SSD solutions.
IDE vs AHCI:
Iometer Benchmark Summary
Using Iometer Benchmark the reported performance gain favored AHCI, Reported AHCI performance increase against IDE is Total IOps: 190%+
Total MBps: 190%+
Avg IOPS Response Time: 190%-
Max IOPS Response Time: 15%- CPU Utilization Time: 15%-
SATA Mode Recommendation: ACHI
So Overall you can see that AHCI mode wins over IDE mode and there is huge performance gain.