AB9 QuadGT Overclocking

[Methadras]

I have an AB9 QuadGT running an E6700 @ 3.5Ghz @ 1.425v. It's watercooled using a Swiftech Apogee Drive. I've lapped the CPU down to 10000 grit paste on a lapping plate and it has a finish of around 6 - 8 RMS with a flatness tolerance of .0002 from corner to corner. I'm using 8GB of DDR2-800 G.Skill 5-5-5-12 @ 1:1 @ 2.15v. My current temps using CoreTemp are at 39c - 41c idle and 42c - 45c at load. At least CoreTemp isn't showing that I've gone any higher than that. I'm also running a 8800 Ultra in the loop and it's overclocked as well.

My question is, is that I think that this CPU can actually give me more, however I don't know about the ram. I'm sitting at 1:1 right now with an FSB of 350 @ 1:1. Should I be running 1:1 or 2:3? I also have a 4:5 modifier as well. What is the general consensus on running this ratio and what should I be using overall? Thanks for any input.

 

[silverphoenix]

From my experience with this board your ram should be fine they are rated for 400FSB anyhow, but the board can get a little picky if you choose another divider other than 1:1 at higher FSBs. I could only run 1:1 stably at 450FSB when I had the board.

 

[Methadras]

From my experience with this board your ram should be fine they are rated for 400FSB anyhow, but the board can get a little picky if you choose another divider other than 1:1 at higher FSBs. I could only run 1:1 stably at 450FSB when I had the board.

I'm not sure I understand. Right now I'm @ 350 FSB x 10 CPU Multiplier @ a 1:1 ratio. I understand the ram is rated at 400 FSB, but where should I be with respect to setting the FSB on this board? Should I up it or go 2:3 ratio?

 

[silverphoenix]

I'm not sure I understand. Right now I'm @ 350 FSB x 10 CPU Multiplier @ a 1:1 ratio. I understand the ram is rated at 400 FSB, but where should I be with respect to setting the FSB on this board? Should I up it or go 2:3 ratio?

if your doing only 350Fbus then go ahead and up the divider and see if it runs stably, it should.

 

[Methadras]

if your doing only 350Fbus then go ahead and up the divider and see if it runs stably, it should.

Which one, 2:3 or 4:5? Also, why wouldn't I leave it at 1:1? I'm trying to understand the connection between 1:1 and how it relates to CPU:ram as a benefit to overclocking and what performance hits or gains you can get out of that or by going to another divider. What does it mean going from 1:1 to 2:3 performance wise?

 

[silverphoenix]

Which one, 2:3 or 4:5? Also, why wouldn't I leave it at 1:1? I'm trying to understand the connection between 1:1 and how it relates to CPU:ram as a benefit to overclocking and what performance hits or gains you can get out of that or by going to another divider. What does it mean going from 1:1 to 2:3 performance wise?

Well the core 2 architecture started off using the 266fbus quad pumped, meaning it ran at 1033. By running you fbus at 350 your technically running your cpu at 1400. 1:1 ratio is a tad bit misleading as memory is dual channel so running memory at 350mhz you get 700mhz effective, by running it at a higher divider(for intel) such as 2:3, or 4:5 or 2:1 you are running the memory faster to try to match the cpu. 2:1 the memory would be matching the cpu and this is very hard to do with DDR2 and an oc'ed cpu. You'll see some performance benefits in memory bandwidth if you can raise the multiplier from 1:1.

 

[Methadras]

Well the core 2 architecture started off using the 266fbus quad pumped, meaning it ran at 1033. By running you fbus at 350 your technically running your cpu at 1400. 1:1 ratio is a tad bit misleading as memory is dual channel so running memory at 350mhz you get 700mhz effective, by running it at a higher divider(for intel) such as 2:3, or 4:5 or 2:1 you are running the memory faster to try to match the cpu. 2:1 the memory would be matching the cpu and this is very hard to do with DDR2 and an oc'ed cpu. You'll see some performance benefits in memory bandwidth if you can raise the multiplier from 1:1.

Ah, excellent explanation. That is what I was looking for to coalesce in my mind what was going on and why. So in your last sentence you are saying that if I went to 2:3 I will see some performance benefits? How about 4:5?