RAM speed issue.

[xxpantherrrxx]

So when i first built my rig, AMD FX 8320 CPU, MSI 970A G46 mobo I had gone with a 2x4GB Crucial Ballistix kit which was rated as DDR3 1600mhz, today I went out and purchased another kit of 2x4GB Corsair Vengence DDR3 1600, and for some reason the Vengeance sticks will not run at 1600mhz, I have tried setting the speed in the BIOS to DDR3 1600 yet those two sticks are not running at what they are rated for, I am at a loss now. Any one have any ideas?

 

[Otto Dafe]

Mixing memory from different manufacturers is not a good idea. I would try to return the Corsair and get a kit from Crucial identical to the one you have. Be aware though that two 2x4 kits aren't necessarily meant to be run 4x4.

 

[xxpantherrrxx]

Unfortunately finding sticks that are similar is going to be a tough find as when I built my machine it the Crucial Ballistix were on clearance at tigerdirect retail store, since then I have looked for matching ones and haven't been able to find any. Ugh I guess I will see what I can do.

 

[xxpantherrrxx]

Update: I fixed the issue! What I did was I had the crucial ballistix in the bootable DIMM slots and when I added the corsair vengeace to the remaining two slots, I just flip flopped the DIMM slots, I moved the corsair into the bootable DIMM slots and the crucial into the other and now RAM speed is 1600mhz, thanks for everyone's input.

 

[Albuquerque]

It may have been an XMP / UEFI / BIOS combination issue rather than a specific "which slot is it in?" issue. Running four channels of ram will always have more stability "challenge" than two channels. What you likely did is put the sticks with the slightly-slower XMP profile into the first and third slots, which may have then relaxed the auto-discovered timings for the entire set.

It shouldn't work that way, but it may be a hiccup in the firmware on your motherboard.

For the record, I've got an Intel DX79Si board that is running eight sticks of ram in quad-channel mode at 1666 with 7-8-9-1T timings; I never expected a quad channel consumer board to be that stable at this price point. Speaks volumes about the quality of the board AND firmware, IMO...

 

[xxpantherrrxx]

It may have been an XMP / UEFI / BIOS combination issue rather than a specific "which slot is it in?" issue. Running four channels of ram will always have more stability "challenge" than two channels. What you likely did is put the sticks with the slightly-slower XMP profile into the first and third slots, which may have then relaxed the auto-discovered timings for the entire set.

It shouldn't work that way, but it may be a hiccup in the firmware on your motherboard.

For the record, I've got an Intel DX79Si board that is running eight sticks of ram in quad-channel mode at 1666 with 7-8-9-1T timings; I never expected a quad channel consumer board to be that stable at this price point. Speaks volumes about the quality of the board AND firmware, IMO...

Yea I have no idea but the RAM speed is now reporting as 1600mhz instead of 1333mhz. I think maybe part of the issue was that the SPD of the Corsair Vengeance RAM was 1333 and the speed was 1600, the crucial SPD was 1600 and speed obviously 1600.