Raid 0 + AHCI?

[society misfit]

So I picked up a pair of Corsair Force 120Gb SSD drives and set them up in RAID 0. Figured I could just slap them in, load the AMD RAID drivers then do a clean install of Win 7. Which I’ve done and everything seems to be working fine. Now reading about the performance benefits when setting your drive controller to AHCI within Windows. My question is, can I still set the controller to AHCI within Windows even though I’ve configured the drives in a RAID 0? The BIOS only allows 3 choices, IDE, RAID and AHCI. It’s a Asus M4A7TD EVO Motherboard (AMD 870/SB 850 chipset)

 

[society misfit]

Thanks for the reply but still didn’t really answer my question. My BIOS is set to RAID 0 for my 2 SSD. I assumed that setting this to AHCI within the BIOS I would lose the RAID and therefor have to reinstall Windows. However, the many SSD tweaks that I’ve read (http://www.sevenforums.com/tutorials/70822-ssd-tweaks-optimizations-windows-7-a.html) state to set your IDE ATA/ATAPI Controller within device manager to AHCI. Would this not conflict with what the BIOS is set at?

 

[WindowsStar]

You can pick RAID or AHCI not both. When you pick RAID most times Windows will install a RAID driver that gives performance like the AHCI or better.

If you want AHCI you will need to break the RAID and reload Windows. -WS

 

[Packet]

On PC's, the implementation of RAID is a superset of AHCI.
or alternatively, AHCI is a subset of RAID.

since you have your BIOS already set to RAID, you're good to go. you're getting all the NCQ and other AHCI jazz.

Even though RAID-0 is... well, i hope you have good frequent backups.

 

[pparks1]

Just as packet explained, my understanding is that with RAID chosen, you will get the benefits of AHCI.

 

[DeaconFrost]

Took a few posts, but the correct info got out there. AHCI and RAID are two different settings, as explained above. You can set your BIOS to one or the other. You could have seen this by going into your BIOS and looking through the controller options. The "tweaks" you read about were concerning systems without arrays, and just drives used as separate drives.

 

[DeaconFrost]

If he wants to run in AHCI mode and lose the RAID functionality, yes. I'm a firm believer in the Anandtech tests that prove RAID0 is a waste in a desktop environment. However, that was with mechanical drives. I'm not sure about SSDs, but if it was me, Instead of buying two drives, I would have just bought a single larger one and run it in AHCI.

 

[pparks1]

If he wants to run in AHCI mode and lose the RAID functionality, yes. I'm a firm believer in the Anandtech tests that prove RAID0 is a waste in a desktop environment. However, that was with mechanical drives. I'm not sure about SSDs, but if it was me, Instead of buying two drives, I would have just bought a single larger one and run it in AHCI.

Agreed, it looks great in benchmarks...but real world performance?????? With the OS and such, it's not about fast sustained writes, but rather fast random I/O...and the RAID configuration isn't helping in that area.

 

[WindowsStar]

On PC's, the implementation of RAID is a superset of AHCI.
or alternatively, AHCI is a subset of RAID.

since you have your BIOS already set to RAID, you're good to go. you're getting all the NCQ and other AHCI jazz.

Even though RAID-0 is... well, i hope you have good frequent backups.

+1

 

[WindowsStar]

Just as packet explained, my understanding is that with RAID chosen, you will get the benefits of AHCI.

+1

 

[Golden]

Agreed, it looks great in benchmarks...but real world performance?????? With the OS and such, it's not about fast sustained writes, but rather fast random I/O...and the RAID configuration isn't helping in that area.

I think this sums it up nicely : from what I have read, the benefits from RAID'ing SSD's are negligible, especially from an OS standpoint given the majority of IO is read.

On mechnical platters, its a different story depending on your needs (I use RAID0 on mechanical drives for a very specific bit of work where the write activity is extremely high, and the benefit of RAID has been demonstrated to offset the risk).

 

[society misfit]

Thanks for everyones input. The reason for the two 120GB drives was the cost. A local store had them on sale. A 240GB drive was just too expensive. I could have purchased 3 Corsair Force 120GB drives for the price of 1 240GB drive of the same model. And a single 120GB drive just wasn’t enough disc space.

I ran DiskMark in IDE mode on 1 drive when I first got them. Obviously it out performed my current HDD but it was nowhere near what I expected (sorry I don’t have that benchmark). Once I configured RAID the performance increase was amazing!!! Unfortunately I did not test in AHCI prior to setting up the RAID

I’ve yet to find any tests between AHCI and RAID0. But the ones I’ve seen between AHCI and IDE do not show that great of a performance increase

SSD Benchmark Tests: SATA IDE vs AHCI Mode | AHCI vs IDE,SSD,AHCI,IDE,SATA,Solid State Drive,Benchmark Performance SSD Testing AHCI vs IDE,Benchmark Performance SSD Testing: Intel ICH10 SATA AHCI vs IDE Mode Speed and IOPS Comparison

I’m quite happy with the performance I get out of my 2 SSD’s in RAID 0 (yes i perform frequent backups), was just inquiring if I could squeeze any more performance out of my set up if I could set AHCI with RAID. Not to mention I was a little puzzled with this AHCI stuff!! Thanks again.

Below is my CrystalDiskMark results.

 

[Golden]

Hey, at least it works

I'd be quite interested to compare your results to some that I have, using the winsat Windows command like this:

1. Open an elevated Command Prompt
- Start Orb, type cmd in search box, righ-click on cmd and click Open as administrator
2. Type winsat disk
3. Take screencapture of result and upload here.

Regards,
Golden

 

[society misfit]

Hey, at least it works

I'd be quite interested to compare your results to some that I have, using the winsat Windows command like this:

1. Open an elevated Command Prompt
- Start Orb, type cmd in search box, righ-click on cmd and click Open as administrator
2. Type winsat disk
3. Take screencapture of result and upload here.

Regards,
Golden

Here ya go! Would you mind posting yours as well for comparison? Thanks

 

[Golden]

This is my single ACHI connected OCZ Vertex2 60GB SSD, and my 2 x Samsung F3 SpinPoints in RAID0.

See any significant difference between RAID'ing and not RAID'ing SSD's?

 

[society misfit]

Not sure what I’m comparing here. By the looks of it a SSD in RAID0 compared to a 7200 HDD in RAID0 shows a difference across the board. However, a SSD in RAID0 compared to a SSD in AHCI shows advantages in both formats. But we are comparing 2 different drives so it’s hard to tell the advantages of either or. I ran that test on a WD 1TB Green drive…too pitiful to even post! But it works great as a storage/backup drive.

My post was inquiring if AHCI could be turned on with a RAID config only because of all the SSD tweaks I’ve read on the net. Some do mention RAID but don’t go into detail…hence my confusion. I’m quite happy with my RAID0 set up. It performs like anything I’ve ever experienced on a PC. Im not too concerned about the risk everyone goes on about with RAID0. IMO a single drive in non RAID is at the same amount of risk as 2 drives in RAID0. You lose one you lose it all!!!! Besides I do perform frequent backups of my files.

Thanks again.

 

[Golden]

Hi,

Sorry, I seem to have caused confusion by posting my mechanical RAID setup in addition to my SSD setup - ignore that RAID one for the time being. I put it up there for an additional comparison.

You should be comparing your SSD result (your image) against my SSD result (my first image) - I don't see a significant difference between them.

You have a choice of either ACHI or RAID, but not both.

Regards,
Golden

 

[Lorider]

Raid vs ahci

I Have two PCs that I build using the same Circuit board Asus P5K-E one of em Raid0 the other AHCI, the RAID 0 is much faster for editing video and working with large files, I always backup my system. epically the RAID 0 !!