Finally! 175 FSB on my Epox 8K7A

[Len]

I'm now at 1400 (175 *8) using 8-8-8-3-7-2.5-3 it works. I had been using AUTO mem timings in the past but they don't even work for me at 167 Mhz. I'm trying for better mem timings. I'm testing 8-8-7-3-7-2.5-3 now. I know 8-8-7-2-7-2.5-2 will NOT work. Already tried CAS2 and WinME load, everything runs ok (Q3, UT, 3dmark 2001) but Prime95 errors on the very first test

Question:
At 175 PCI bus is 35 Mhz (175/5) but what is my AGP speed? How is AGP calculated in relation to PCI and/or FSB speed?

 

[Pitspawn]

Your AGP speed is equal to 2/3 of your fsb.

This means if you are running at 100FSB you are running at 66.66Mhz AGP.

This means at 175FSB your 116.66Mhz unless you have an AGP ratio adjustment (I doubt it). No video card hits that, ever.

 

[JuDgE_DrEaD]

Thats quite an overclock Len, way to go, mind posting some pictures?

PS - Just kind of hard to believe since the limit FSB for this board is 166

 

[Tacoman667]

Not really, considering the new BIOS allows for the /5 and /6 PCI clock now. It will go all the way to 250FSB but I haven't seen anyone past 207 yet. Gotta wait for the faster RAM to run it higher. Maybe this means that the 8K7A might have support for the new DDR333 RAM soon. That would be coolio. Hey Len, have you tried lowering your multiplier by 1 notch and then trying to up the FSB again? Maybe your CPU is holding you back.

 

[Len]

I tested lots of memory timings and the fastest which runs P95 (seems to be hardest on memory) is 8-8-8-3-7-2.5-2.

Anyone else know about the AGP speed? I doubt it can be 2/3. It *might* be 2/PCI divisor or 2/5 in my case. That means at 167 (where the 1/5 PCI kicks in) PCI=33.3 and AGP=66.6 (both in spec).

The latest 1711 BIOS supports up to 250 FSB and the 1/5 and 1/6 PCI divisor. Check out some of Wild_Andy_C's posts here. He's got some special DDR RAM that does over 200 Mhz.

I haven't tried a lower multiplier yet. I figured my memory could handle it but I guess I could try for fun. I like to keep my PCI & AGP speeds down so I don't like to push it too much. I know my CPU tops out around 1420 at 1.95v so I could just keep it as close to that as possible.

One other thing, I noticed my CDRW drive will NOT run with DMA enabled at this FSB. Is it ok to run a burner without DMA enabled? It seems to read ok but I haven't tried burning a disk yet.

 

[Bobby Manus]

Where can I get a good link on the memory timings you guys are using? I only understand it as cas 2 or cas 3... I see you guys posting a lot of numbers that dont makie much sense to me. My mobo only allows me to adjust cas 2 to cas 3... I think =.

 

[Tacoman667]

DDR RAM has more timings that you can adjust in the BIOS. I haven't used any other DDR motherboards but I know this to be true on the EPOX 8K7A. Sometimes those choices can be a pain though. Unlike SDRAM where you only have 3 options to mess with when something goes wrong, you have 7 on the DDR RAM and so many number of sequences to screw with. That can really be a drag. I don't think anyone really even has a full understanding of all those timings yet anyways.

 

[Len]

I tried 187x7.5 = 1402 with 8-8-8-3-7-2.5-3. It seemed to work for a while. Prime95 ran for about 20 mins and then the PC froze. I rebooted to lower FSB in the BIOS and it froze in the BIOS too. I had to let it cool off for a while then drop the FSB back down to 175. I had MBM5 running so I know the CPU temp was 48C when it locked. That's a normal load temp for me so I think it was the mem that gave out. If I knew what more conservative memory timings were I'd try 187 again. Maybe 8-8-8-4-8-2.5-4?? I'm really not sure.

About what the memory settings mean, I really don't know. I just learned what has worked for others and went from there with trial and error. I don't think the 8K7A memory settings are documented well anywhere.

Even at 176 x 8 = 1408 with 8-8-8-3-7-2.5-2 I got a prime95 error after it ran for almost an hour. It usually errors within the first 15 mins or so if its going to error at all. I know Prime95 ran all night at 8-8-8-3-7-2.5-3 so maybe I'm just going to aggressive on the memory timings. So I guess 176 x 8 isn't quite 100% stable for me even though it runs UT, Q3 and 3DMark 2001 without any problems.

 

[Tacoman667]

I feel, however, that if your memory boots at a certain speed and gets into windows and gets into other programs within windows, then it's not the speed of the RAM or even the RAM at all giving problems. Drop the mult to 7.5 and do 180FSB and test it. Does it work? Have you thought about lapping the HSF on the chipset itself? I lapped mine and it runs a little cooler and I found out that the HSF on the northbridge is concave! I lapped that sucker flat as hell and now I am stable but my CPU or other components are keeping me from going higher. Maybe the temps are your problem. Try a different approach.

 

[Tacoman667]

By the way, do you have the Auto Detect DIMM/PCI Clk option in BIOS on disabled? I can't seem to get my FSB to 167 at all. Mine is enabled though, maybe that is my problem. I got my system to 160FSB now and testing stability and my memory settings are 8-8-7-2-2-2.5-2.

 

[Len]

My Auto detect is enabled and always has been. I suggest trying 8-8-8-3-7-2.5-3. If I set the middle 3 to a 2 then it is not stable. If I set the 3 on the end to a 2 it is about 99% stable but Prime95 will eventually generate an error. I will probably drop it back to 3 for stability. That's a bummer because using 2 gives me a nice boost in performance (see below).

Here are some of my benchmarks:

1415 (149 x 9.5) 8-8-6-2-2-2-2
Sandra 676/903, 3Mark2001=4664, UTBench=?

1400 (175 x 8.0) 8-8-8-3-7-2.5-3
Sandra 716/904, 3d2001 = 4725, UTBench=52.09

1408 (176 x 8.0) 8-8-8-3-7-2.5-2
Sandra 753/950, 3d2001 = 4800, UTBench=53.95

 

[Bobby Manus]

O wow so the higher the memory timings numbers the faster it is? Are the begining numbers always 8? i noticed that everyons first 2 numbers were 8 so far.

 

[M@€$†®Ö™]

Very impressive overlock. !!!!

Maestro

 

[hooziewhatsit]

thhpppptttttt!!!
lol, j/k, very nice OC!

here I am stuck at 100Mhz fsb.....

 

[Bobby Manus]

I dont know if you guys read the intel forums much but basically they cant unlock the multiplyer on a p3 and so they do all there overclocking by fsb. Its not to rare at all to find p3 overclockers at 180fsb. Ive heard someone say geforce 2 ultras (my current gpu) can take 180fsb np. (I think he meant 180 for the board, then 2/3 of that for the agp slot making it 118fsb for the agp slot.) This is what len is running, so his FSB's are still very resonable as far as waht ive heard.

 

[TRANCER24]

I just got the 8K7A today and put it together i love this board much better then my A7V 133 that i had forget asus they suck compared to this MoBo. I just don't know why i can't get any faster FSB then 122 stable unless i up my voltage i am at 1.75 and im using duron 700 with crucial pc 2100 it just doesn't like fsb overclocking much . Maybe i just got an unlucky chip well atleast i know this board pushes better then my Asus that i could only get 105 fsb overclock with this same CPU that goes to tell you something this board is much better then my old A7V

 

[Bobby Manus]

Better overclocker then the a7v? Oh my I always looked as the a7v as the purest overclocking mobo ever made! Not necisarily for ram, but just seemed like the highest mhz overclocks always came from that board. Then again sdram was like so totaly last month =)

 

[wild_andy_c]

Bobby Manus (Jul 29, 2001 04:04 a.m.):
Better overclocker then the a7v? Oh my I always looked as the a7v as the purest overclocking mobo ever made! Not necisarily for ram, but just seemed like the highest mhz overclocks always came from that board. Then again sdram was like so totaly last month =)

The A7V is a poor board by comparisson to all of the DDR boards due to the fact that its two phase power supply wanes par the wayside when pitted against mosfetted 3-phase solutions that support Morgan and Palomino.

Re. the AGP divisor, that does alter in the same fashion as the PCI divider automatically, however I don't know the actual speeds at which these initiations occur due to my current inability to read chinese (I am learning though)

 

[Len]

Bobby Manus (Jul 29, 2001 12:16 a.m.):
O wow so the higher the memory timings numbers the faster it is? Are the begining numbers always 8? i noticed that everyons first 2 numbers were 8 so far.

Based on trial and error I think the first number higher is faster then all the rest lower is faster. Optimal memory timings that will work on most systems is 8-8-6-2-2-2-2 or maybe 16-8-6-2-2-2-2.

About AGP speed, this is turning out to be quite a mystery. Some here think is FSB * 2/3 (117 at 175 FSB). On another message board they said FSB/2 which would be 87.5 Mhz for 175 FSB. Maybe I should ask Epox tech support. It just seems strange to me that they would implement a 1/5 PCI divisor on the 8K7A but not have it affect AGP. I thought the logical approach would be to relate AGP to PCI speed such that whenever the next higher divisor kicks in (1/5 at 166 and 1/6 at 207 Mhz) then *both* AGP and PCI would be in spec at 66.6 and 33.3 respectively. But so far it seems that AGP might not be related to the new higher PCI divisors.

One other comment ... its great to reach these high FSB speeds but having to reduce the memory timings so much negates a lot of the advantage. For example, I've notice that memory and game performance is very similar at 157 x 9 = 1413 using 8-8-6-2-2-2-2 and 175 x 8 = 1400 using 8-8-8-3-7-2.5-3. This makes me wonder if its really worth it all.

 

[Tacoman667]

Well, I have the same feelings as well. I would like to know where I could find some PC2700 RAM like wild_andy_c has but I guess that's just a distant thought for the rest of us. PC2400 RAM goes up to 150FSB at CAS 2 right? I think I am going to try it out then. Too bad Corsair are the only manufacturers of it though, unless I am wrong.