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I have a Mushkin Enhanced Chronos 120GB SSD ( Its performance is rated as:

Capacity: 120GB

Read Speed: up to 550MB/sec

Write Speed: up to 515MB/sec

Controller: SF-2281

Interface Type: SATA 3.0 (6Gb/s)

IOPS: 90,000 (4K random write, 4K aligned)

My performance however is much lower.

Screenshots from HD Tune Pro 5.00:

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I am however using this on a SATA2 port, while it is a SATA3 SSD.

The other hardware:

Motherboard: Gigabyte ga-ma790xt-ud4p ( (latest BIOS (F8))

Processor: AMD Phenom II x4 955 BE

RAM: 16GB (4x4) Corsair Vengeance (

Graphics card: ATI Radeon HD4890 1GB (

It has always been this slow, I haven't seen the performance go down since I started using it.


Here's a screenshot from ATTO. It looks a bit better then HD Tune Pro.

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After enabling AHCI:

enter image description here

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I'm curious about an answear, according to wikipedia, SATA2 can reach 300MB/s, while yours is running on 150MB/s only. – Diogo May 4 '12 at 19:20
@DiogoRocha I do get bursts of up to 200MB. – Simon Verbeke May 4 '12 at 19:29
But the average is about 150MB/s, half of nominal capacity. – Diogo May 4 '12 at 19:40
Also run AS SSD benchmarks – Sathya May 7 '12 at 17:10
@SimonVerbeke Cool :-) enjoy your new SSD :-) – Sathya May 7 '12 at 18:35
up vote 7 down vote accepted

The first problem you have is that you are using HDTune for the benchmark. The way it does its benchmarking is to try and map out how the performance of a hard drive changes as you move across the platter. This type of access is a worst case for SSDs and does not lend itself to pushing an SSD as far as it can go. The rating for SSDs are usually done with ATTO Disk Benchmark. As a benchmark ATTO has the opposite problem. It is a best case scenario, which is why the ratings say "up to".

Also, being on SATAII will limit you to around 260-280MB/s.

Another common cause of not getting the expected speeds from a SSD is if the SATA controller is in IDE emulation mode instead of in AHCI mode.

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I remember something about the AHCI mode. I believe I tried to set that when I had recently installed the SSD, but that I kept getting BSOD's while booting and had to disable it again. – Simon Verbeke May 4 '12 at 21:22
Windows does not enable the ACHI drives if you install in IDE mode so it won't be able to boot if you later switch to AHCI mode. The fix is simple and found here That will allow you to enable the Microsoft AHCI drivers. It may still be the case they you'll want to reinstall the platform specific AHCI drivers. – Mr Alpha May 4 '12 at 21:31
I'll first finish this benchmark, and then I'll try turning AHCI mode on. – Simon Verbeke May 4 '12 at 21:35
I thought access time and read speed was the same accross all cells of an SSD - can you explain how this a "worst case for SSD"? – mtone May 4 '12 at 21:56
Enabled AHCI and rerun the benchmark. The results stay the same – Simon Verbeke May 4 '12 at 22:00

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