Maximus VI Formula - RAID 1 and no TRIM

[Ambidexter]

Hi,

I've seen several threads here and on Toms saying that Samsung 840 Pros in RAID 0 work with Intel RST 12.8.x with 12.7 Option ROM.

I've been using two 840 Pro's in RAID 1, on the first 2 Intel ports on my Formula. Testing the trim with a few tools and the hex edit method ... and the fact that the write speed went from 800MB/s to about 120-200MB/s, tells me the trim's not working.

What I've had to do is remove one of the disks from the RAID in the option ROM, take that drive out, secure erase it (but unplug the data cable from the other RAID member and change SATA mode to be ACHI), then change the board back to RAID, plug the good drive (with the OS) back in, reboot into Win8 and let RST rebuild it.

Then repeat on the other drive.

I can't keep doing this though. Windows 8 thinks it's trimming, but it doesn't seem to.

So, would the trim work if I just used the 2 drives as RAID 0 - which, as I said, others say work?

Thanks,

-Ambi

[Praz]

Trim has never worked with RAID1 nor any other type of array other than RAID0.

[Classic_GOD]

Praz wrote:
Trim has never worked with RAID1 nor any other type of array other than RAID0.

I've read somewhere that RAID1 got TRIM support on Intel controllers before RAID0 did but I can find only one source of this info and one source is not enough IMHO.

@OP - I'm not aware of RAID1 configuration that would allow you to surpass write speeds of a single drive in the array (read yes but not writes). I'm not up to date on raid technology but AFAIK you shouldn't get 800MB/s writes on this drives in RAID1.

[Praz]

Classic_GOD wrote:
@OP - I'm not aware of RAID1 configuration that would allow you to surpass write speeds of a single drive in the array (read yes but not writes). I'm not up to date on raid technology but AFAIK you shouldn't get 800MB/s writes on this drives in RAID1.

Non-burst or multiplexed read/write speeds of RAID1 will be slightly lower than speeds achieved with a single disk because of overhead.

[Ambidexter]

To @Op, you're right...I was talking off the top of my head. Looking at my CrystalDiskMarks, I was getting about 500MB/s seq. write with 1000MB files initially, and was getting as slow as 120-200MB/s on seq. write in the last few days. After doing my secure erase dance, it's back up to 540MB/sec or so. Reads go about 1100 after secure erase, to about 850-900 MB/s before (after a month of usage).

I might be able to live with these realities, if they don't get worse. Write perfromance of 130MB/s or so is what I get on HDDs, after all! I'd probably get a separate temp / paging SSD to keep mostly-read stuff on C: and keep the RAID 1 for reliability.

I just don't like that WIndows says it's trimming, but RST doesn't complain. I'd expect an error to be thrown when the optimize is attempted, that would help us know it doesn't really work. Or maybe just grey-out the optimize feature, as it's not doing anything.

Thanks,

-Ambi

[Ambidexter]

Hi Folks,

Just an update. I built a new RAID today with 2 X Samsung 840 Pro 256. This is the same SSDs I use for the RAID 1 that doesn't (seem to?) trim. I ram the trimcheck-0.5 on the new array, and it does successfully trim! And the RAID 1 is still not working.

The write speed is about 2X the RAID 1, as you'd expect. Now that I have 4 SSDs, maybe I'll run RAID 10 or keep the RAID 0 as a boot drive and image the raid 0 to other 2 (I guess in RAID 0 too...if the image backup is above 256GB).

Regards,

-Ambi

[Ambidexter]

Yeah, but a RAID-1 array doesn't work and a RAID-0 array does work...with the same SSDs.

I'd have thought RAID-1 would be easer to trim because there's a "whole disk" not stripes. But then again, I could see in a RAID-0 when the reading or writing stripe is active on disk A, disk B is just "waiting for something to do" so throwing a few trims in then would be easy.

In any case, I may just go with 2 RAID-0s and back up between them.

Cheers,

-Ambi

[Ambidexter]

Well, is there an easy...or documented, way of mving a raid 1 to raid 0? Also, I don't even see the garbage collection making any difference here. I can leave the PC in the BIOS for hours (no activity, but power to the SSD) or leave Win 8 at the welcome/login screen and never see any upgrade in the speed...back to normal.

I will give Asus kudos for providing a built-in way to "unfreeeze" the frozen disk to allow secure erase to work! Thanks Asus!

Cheers,

-Ambi

[Abula]

For ssd raid arrays to have trim working you need to match the intel RST drivers to your BIOS OROM, else the trim command will not be sent under the array. Its not necesarry for all cases, sometimes older can work with newer, but the best is to have matching for the trim command to pass.

Read the following thread, so you get a better perspective, ASUS / ASRock / MSI / GIGABYTE BIOS's with updated RAID OROM