Help me solve this overclocking mystery

I'm a newb at overclocking so bear with me...

I have a 2.8C P4 - SL6Z5 Spec - M0 Stepping CPU
2 x 256MB HyperX KHX3200K2 PC3200 2-5-2-2 @ 400FSB
Abit IC7-G with Rev 19 BIOS

I am trying to work with the tightest timings possible on the memory while overclocking my CPU.

I can overclock the CPU to 265FSB (havent tried higher) @ 1.525V which runs at 60* C with Prime95 running in Max Heat mode and a looped Quake 3 Timed Demo. This is with the memory at 4:3 to eliminate it from holding me back.

I can overclock the Memory to 212FSB @ 2.8v w/ 2-5-2-2, GAT - F1, Auto, 3 Clks, Auto, Auto when running at 1:1 ratio.

But when I try to combine the two...

FSB @ 265 : 212 with 5:4 ratio but it wont boot into Windows.

If I set the memory to 2-5-2-2 GAT - Auto, Auto, Auto, Auto, Auto
it boots fine.

If I set GAT to anything other than Auto, the system will not boot...

What is my bottleneck here? What am I doing wrong?

-Josh

Would I be better off returning the board and memory for a IC7-MAX3 and Corsair XMS4000 1GB Kit? It'd only be another $130 for an extra 512MB of RAM and a board with better VDIMM settings. Will the XMS4000 run at 265FSB with default timings and GAT? What kind of voltage can the XMS4000 take?

Are there any good articles with benchies on the difference between a P4 @ 800FSB - DDR400 2-5-2-2 versus P4 @ 1000FSB - DDR500 3-4-4-8? Which would be faster for games and general usage in Windows? Looks like I got a decent proc, wanna take advantage of it!

I think you are trying to run too tight of timings and the GAT settings are holding you back. Try this to see if I'm right. Set the GAT to auto,auto,auto,disable,disable. If you are running the vdimm at less than 2.7v, bump up the vdimm to 2.7v. Stay with the 5:4 memory ratio if possible. Try relaxing the RAM timings a little, like maybe 2,3,3,6. These IC7 mobos almost never like the RAS to CAS delay at 2 unless you volt mod them. Report back with what happens and we'll go from there.

5:4 with tight timings is supposedly better then 1:1 with relaxed timings.

Now that OCZ EB is out, not sure if that's true, haven't read too many reviews on that yet. I may like them and feel the need to upgrade

Well, I ended up returning the HyperX and ordered some OCZ PC4300EL to run at 1066FSB 2.5-4-4-8 1:1 with my CPU. I hope it works...

Okay, so I got the OCZ, but I can't run it at default rated speeds either!!! Argh! What is holding me back? I can run at 265MHz FSB in 5:4 and 4:3 but not with 1:1. Is this Motherboard holding me back (IC7-G)? What is a better board that will let me run at 265MHz+ FSB 1:1 @ 2.5-4-4-7?

You might try rereading my last post in this thread.

Tried running at 265MHz FSB @ 2.5-4-4-7, GAT - All Auto (Also tried AAADD, 2.8 VDIMM. I refuse to use 5:4 ratio. I want to stay at a 1:1 ratio. I know the RAM can go higher and the CPU can run at this speed stable for 48 Hours running Prime95. Its gotta be this motherboard. Any other ideas?

If you haven't updated the BIOS, then do that first.

Why do you "refuse" to use the 5:4 ratio. The P-4 loves the 5:4 ratio. If you are a former AMD dude, then I might understand because AMD prefers 1:1, but really it's been proven time after time that there is not much difference with Intel systems using the 5:4 ratio and tight timings.compared to the 1:1 ratio and relaxed timings. If you "have" to use the 1:1 ratio, then you better get some PC4000 or better RAM.

I just prefer to run a synchronized Bus and don't understand why I have to loose the speed of one component when I know they run at full speed on their own. I dont mean to be offensive, Im just having a hard time with this system and Im loosing my patience... I purchased OCZ PC4400EL for 266MHz FSB @ 2.5-4-4-7 @ 2.8v. The system cannot run reliably at 266MHz FSB 1:1... If I had to run at 5:4 I would either loose Memory bandwidth or CPU speed, that is why I don't want to run asynchronis.

Ok, I missed your middle post that said you got new RAM. He, he, he, no wonder I was amazed... I thought your PC3200 was hitting 265 FSB. Yep, with PC4400, I would refuse to use anything but the 1:1 ratio too.

All I can say is disable the last two GAT settings and try 3,4,4,8 timings @ 2.8v. Anything above 250 FSB with a 2.8C is excellent.

batboy said:

I think you are trying to run too tight of timings and the GAT settings are holding you back. Try this to see if I'm right. Set the GAT to auto,auto,auto,disable,disable. If you are running the vdimm at less than 2.7v, bump up the vdimm to 2.7v. Stay with the 5:4 memory ratio if possible. Try relaxing the RAM timings a little, like maybe 2,3,3,6. These IC7 mobos almost never like the RAS to CAS delay at 2 unless you volt mod them. Report back with what happens and we'll go from there.

Click to expand...

I tried your suggestion and it worked great for me. I can get an extra 2 Ghz ,but not stable. An extra Ghz stable though (3.2 @ 3.71). Thanks a bunch, maybe I'll up the voltage as I think it's just a tick above stock, but I'm happy with it...for now.