DDR2 800 showing up as DDR2 775?

[Topochocolate]

Hey guys. I just built a new box the other day. I used an AMD processor for the first time ever, and I've got a potential issue with the RAM. I used two 1 gig sticks of DDR2 800, however in my system it's showing up as DDR2 775. Is this an issue with voltage? Or perhaps maybe this is just normal?

This is the mobo I've got:

http://www.gigabyte.us/Product...ew.aspx?ProductID=2527

And the RAM I used:

http://www.corsairmicro.com/_d...ts/TWIN2X2048-6400.pdf


Any ideas? Thanks guys.

 

[videogames101]

if you buy DDR800, that means it's rated to go up to that speed, but you have to change it in your bios options to DDR800, instead of whatever your motherboard comes set at.

 

[Topochocolate]

Hmmm... I'll check that out. I guess it just confuses me because DDR2 775 isn't an actual speed of memory as far as i'm aware.

 

[videogames101]

No, it's not a speed that i've ever heard of. Also if the sticks are not already in the correct slots for duel channel, try putting them there. BTW, i don't rly know alot about memory problems, these are rather generic solutions...

 

[Topochocolate]

Yea they're running in dual-channel.

 

[videogames101]

yep, i'm stumped

you could try changing the voltage a small bit, see if the speed goes up or down, other then that idk

 

[Topochocolate]

Alright, guess I'll give that a whirl. Thanks.

 

[firewolfsm]

It's because your processor has a half multiplier, the ram will run at 775, deal with it, that's a 4% decrease in bandwidth which translates to a .5% decrease in performance.

 

[tcsenter]

You installed the modules in slots 1 and 2, right? That is recommended by Gigabyte when using two modules, though slots 3 and 4 are also supported.

 

[Topochocolate]

Yes they're in slots 1 & 2. I actually mis-typed the original post, it's "757" not "775". Inverted my numbers. I still feel this is kind of strange. Thanks for the replies though.

 

[myocardia]

Originally posted by: Topochocolate
I still feel this is kind of strange.

It's a bit strange, but it's completely normal for your processor. Don't feel bad, though, all Athlon 64's are that way.

 

[Topochocolate]

Originally posted by: myocardia

Originally posted by: Topochocolate
I still feel this is kind of strange.

It's a bit strange, but it's completely normal for your processor. Don't feel bad, though, all Athlon 64's are that way.

Interesting, thanks!

 

[DrMrLordX]

You can fix the problem by messing around with different combinations of CPU multipliers, memory ratios, and HTT speeds. My X2 consistently underclocks memory unless I use the 1:1 (DDR2-400) ratio and the right multipliers.

It may seem like you'd be losing performance due to reduced bandwidth, but that is not likely the case. You are suffering performance loss due to increased latency. Compensate by tightening timings, if possible. If you're already running at 3-3-3-5 and with every other obscure timing option in your BIOS at its fastest, then you should mess with HTT speeds a bit until you're at DDR2-800; you won't get reduced latency (as measured in cycles), but your CPU performance will, and you'll have the satisfaction of running your memory at spec.

 

[Yellowbeard]

This divider table may help as you try different settings.

http://forum.abit-usa.com/showthread.php?t=109155