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.
Best Answer
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.