Z Turbo Drive Quad Pro was Fast, but Now has Poor RAID 0 Performance
I am having a peculiar problem. My PC is a Z840 dual processor machine and am running Windows 10 for Workstations. About 9 months ago I added a Z Turbo Drive Quad Pro card populated with four 512 GB SM951 modules to my Z840. I added the card in the suggested PCi slot, Slot 6, which is a PCIe3X16 slot. I used Windows Drive Manager to create 4 drive stripped (RAID 0) volume. I checked the speed of the volume using AJA system test, and it recorded a 5853 MB/SEC write score and a 5405MB/SEC read score, which is about where the card should perform. Crystal Disk Mark posted similar scores.
A couple of days ago I ran the test again and to my surprise the card was 1711 writes and 1899 reads, which is about what one SM951 should be. Crystal Disk Mark posted similar scores.
I begun to try to fix the speed decrease. I deleted the stripped volume and recreated it. The scores remained the same. I then configured the 4 drives as simple drives, and they all recorded over 2000 for reads and about 1600 for writes, which is about right. So it seems the problem is not with the drives themselves.
I looked in my bios, which is the latest, and slots Slots 6 is recorded as operating at 8G and PCLe 3x16. I only have two other cards: my graphics card and an HP Thunderbolt card. Both seem to be working fine.
I also took the card out and reseated it. This didn’t help.
I have yet to try a different PCLe 3x16 slot as one is occupied by my graphics card (Slot 2), with would probably hit the SATA cable headers if it was moved to Slot 6, and the other PCLe 3x16 slot (Slot 5) is next to my Thunderbolt card, which would result in the two cards and their fans directly facing each other.
I also have yet to do a bios downgrade.
In short, my Z Turbo Drive Quad Pro was working in RAID 0 as it should. Now its speed is that of a single SM951. As I mentioned, if the drives are set up as 4 separate (non-RAIDed) drives, they work as they should. However I don’t want to have four separate drives. I want a single 2T RAID 0 drive with 6 G transfers as it had.
