What could cause slow SSD performance?

Question

I recently upgraded my Windows XP (!) computer to a single Crucial M4 SSD. The system is running very fast and without problem, but running HD Tune Pro (and CrystalDisk) revealed that sequential read rate is only 80MB/s (with a block size of 64K) and write is 60MB/s. Also, IOPS is only 6,000 (for 4KB). This too seems very low.

There are two SATA controllers (why?) on the motherboard: Promise and VIA. The spec ( http://www.asus.com/Motherboards/AMD_Socket_939/A8V_Deluxe/#specifications ) suggests that the Promise controller (which I am currently using) could be limited to SATA 1.5. However, if that were the case then the transfer rate should be much higher, I think. 1.5 Gb/s = 187.5 MB/s. Also, why is the IOPS so low? (6,000 * 4KB = 24MB).

Research on the internet suggests the performance should be over 400MB/s, so the drive should be much faster.

Currently using the Promise SATA port. I tried plugging the SSD into the VIA SATA port on the motherboard, but I get a bios error "No BIOS is installed." and it will not boot. It's strange because when there is no hard drive installed I get "No hard drives found."

I installed the Promise 378 drivers during the Windows install.

Do you think there is a problem with Windows XP, or perhaps the drivers? Could the motherboard be set up for RAID? I tried changing the settings, but it didn't help.

Solution 1

How did you perform the upgrade and the copy process from your old HDD to the SSD?

If you don't use a tool that is aware of the SSD special properties like the requirement for correct partition alignment you will loose a lot of speed.

Additionally you should always use your southbridge SATA ports for SSDs. As long as you don't own a special PCI-E 4x controller card the southbridge will be faster. Using this port you can get up to 200-300MB/sec; the maximum speed is not possible because it is only a SATA-3Gbit port.

And make sure the southbridge SATA port is set to AHCI not IDE.

Solution 2

Please update to the latest firmware and check again.

Comments

[surfasb]

Something wrong with XP?? You dare say a 12 year old OS isn't perfect!?

[B Seven]

Actually XP is awesome! I just didn't know if there could be issues since SSD's are new.

[B Seven]

Are both Promise and VIA SATA ports on the motherboard southbridge?

[B Seven]

I did not successfully "migrate" the old system files, so I used the Windows XP installer to format the drive, and went through the long (but fast) installation processs. Can I reformat the drive without going through the whole installation process again? What is the proper way to format the drive so that it has correct partition alignment?

[Robert]

Your system has a VIA southbridge chipset, the Promise is an extra chip.