Installing a new 850 evo with an existing raid 0 ssd array and a raid 1 HDD array....Raid or AHCI?

[beekermartin]

I plan on replacing my existing raid 0 ssd array with the single 850 Evo 500gb drive. I was planning on keeping the Raid 1 HDD array as it is.

I tried to clone the raid 0 ssd array and it appeared to work properly but I am having issues loading windows. I started another thread about that. I am planning on doing a fresh install instead.

Should I leave the Sata setting at Raid when I do the fresh install or change it to AHCI. I assume if I change it to AHCI then my raid 1 HDD array will no longer work. Is there any downside to leaving it set to Raid? Everything I have read states to set it to AHCI for best performance.

 

[boosted1g]

What motherboard do you have.

Most boards with 6 SATA ports have 4 on one controller and 2 on a different one. You should put the single SSD on the other controller using AHCI.

 

[beekermartin]

The motherboard is in my sig. It does have six ports on the Intel controller and 2 extra ports on the other controller. From everything I've read it is best to avoid the second controller. I don't really care about performance with the Raid 1 array. It is just for back up.

 

[beekermartin]

I just did some research on the second controller. It is a Marvell 88SE9172. According to the specs it is capable of Raid 0/1. So I could move my Raid 1 HDD array to the Marvell controller and use the Evo 850 on the Intel controller. I assume each controller can be set to either AHCI or RAID separately???

 

[boosted1g]

Yes it should be able to.

 

[beekermartin]

I will play around with it when I get home from work.

Is there really any performance difference between running RAID or AHCI? In other words if I left the RAID 1 array on the Intel controller with the single Evo 850 I would have to set the controller to RAID. How much of a difference will setting the controller to RAID versus AHCI really make in the SSD's performance?

 

[beekermartin]

I've been doing more research and it appears setting it to RAID or AHCI will give the same results. So I can leave the RAID 1 HDD array on the Intel controller and the EVO 850 should still run perfectly. What I found is that RAID is basically the same as AHCI except it has a bootroom for the RAID software. Or something like that. LOL

Can someone please confirm that?

 

[Kewlx25]

AHCI will probably disable TRIM. At some point in the past I heard that Intel would support TRIM in RAID, but I never heard a follow up on that. I've never been a fan of hardware RAID.

 

[beekermartin]

Another option is I just go back to AHCI and don't use RAID. I can always back up my HDD to an external drive. I have a 2TB usb external drive I can use for back up. I liked the idea of RAID 1 because I didn't have to worry about backing it up.

 

[beekermartin]

I played around with it tonight and did more harm than good. I tried so many things that I ended up screwing up my raid 0 boot drive array! So I had no choice but to do a fresh install on the evo 850. at first I couldn't get Windows to install. I ended up having to disconnect all the drives except for the 850 in order for Windows to install. I did set it to AHCI before I installed Windows. After Windows installed I tried changing it to RAID and connected my raid hdd array but that caused a bsod while booting Windows. I switched it back to AHCI and left the 2 hdd connected. Luckily in Windows the drive showed up and is working as drive F. Only one drive showed up though. I disconnected one of the hdd and the drive still showed up in windows as drive F. So I didn't lose the data on the raid 1 drives but since I setup the 850 as AHCI it appears I can't use the hdd as a raid 1 setup anymore. I think I am ok with that. No more raid for now. I'll just be sure to back up important data to my external drive. I could try using the Marvell controller but I think I would prefer faster boot times and just back up to an external instead. I could always leave both 1tb drives installed and just back up internally. Maybe I'll do that for now. I will have to wipe them and start fresh so they get the proper drive letters assigned to them.

Anyway, in case anyone else comes across this thread I hope my experience helps them. Cloning didn't work for me. Maybe because I was cloning a raid 0 array. I don't know. All I know is the tried and true method of doing a fresh install on a new primary drive is still the best method.