Artefacts with Radeon 9800 using Intel 2.4C

[dp004i]

I've started getting artefacts with my Radeon 9800 Pro (Abit IS7 mobo) after I swapped an Intel 2.4B (133FSB) for 2.4C (200FSB) if I overclock the FSB to anything over 225MHz. The processor runs prime95 for hours with no problems at up to 250MHz FSB, so I don't think it's causing the problem. AGP and PCI frequencies are locked to 66MHZ and 33MHz, repectively. I'm starting to suspect that the prboblem is with the motherboard, but not quite sure yet. Are there any settings I can play around with that might solve the problem?

PS: The artefacts look like those you get when your video card memory is overclocked too high (borken lines and polygons). My card is not overclocked.

 

[jdogg707]

Have you tried another card to see if it really is the motherboard? Have you upped the AGP volatge any at all?

 

[dp004i]

AGP is at stock voltage, haven't had a chance to try anther card, but I'm pretty sure it's not the issue...

 

[Shimmishim]

i think the best way to find out is to stick in another card.

 

[Dman877]

What psu ya got?

 

[dp004i]

Antec TruePower 430 watt

 

[myocardia]

Originally posted by: dp004i
Antec TruePower 430 watt

That's not a good psu, for overclocking a P4. You're probably shorting your video card on 12v power, since the TruePower 430 doesn't have much of a 12v rail at all.

 

[InlineFive]

Originally posted by: myocardia

Originally posted by: dp004i
Antec TruePower 430 watt

That's not a good psu, for overclocking a P4. You're probably shorting your video card on 12v power, since the TruePower 430 doesn't have much of a 12v rail at all.

I agree, consider this 400w Fortron PSU instead.

-Por

 

[dp004i]

Are higher-end Antecs any better? Perhaps the 550 watt model?

 

[ectx]

Are you oc'ing your video card? I have to reduce the oc when I push the fsb higher on all of my systems - amd or intel.

 

[dp004i]

I had it overclocked, but the junk in games doesn't go away if I run the card at clock speeds, unless I reduce the FSB to 225 or less. So, will swapping my Antec Tru430 for True550 help, or do those have weak 12V rail as well?

 

[myocardia]

Antec psu's are great for overclocking AMD systems, since they have such a strong 5v rail, but none of them are good for overclocking P4-based systems. Get this psu, it's by far the best, at any price, for overclocking a P4 (and it costs quite a bit less than a 550 watt Antec): link. As a matter of fact, there are people running their 3.0C's at ~4.0ghz, along with a 9800XT video card, also overclocked, with that psu.

 

[dp004i]

Hmmm, I'm not even sure if it's the PSU - well, unless RAM also uses the 12V rail. When I use 5:4 CPU:RAM divider instead of 1:1 divider, everything runs like a champ at 250FSB. My RAM theoretically should be able to handle 250MHz speed, it's Kingston HyperX 4000. I don't even know if swapping out the PSU is worth the trouble in case it is the component that's causing the problem, I'm only losing about 8% of memory bandwidth if I use 5:4 divider instead of 1:1 divider.

 

[myocardia]

Originally posted by: dp004i
Hmmm, I'm not even sure if it's the PSU - well, unless RAM also uses the 12V rail. When I use 5:4 CPU:RAM divider instead of 1:1 divider, everything runs like a champ at 250FSB. My RAM theoretically should be able to handle 250MHz speed, it's Kingston HyperX 4000. I don't even know if swapping out the PSU is worth the trouble in case it is the component that's causing the problem, I'm only losing about 8% of memory bandwidth if I use 5:4 divider instead of 1:1 divider.

And you waited until your 6th post in this thread to mention that? Thanks for wasting my time, bub.

 

[dp004i]

Sorry

 

[ectx]

Interesting. I am not convinced it is a problem of your ram though. Have you tested your ram using memtest86 (or windows memory tested by ms)?

I always thought video ram oc is the main source of artifacts (gpu oc would produce some slightly different artifacts). I was puzzled as to why I need to reduce oc when I increase fsb. I always thought it is the nb. But what do I know?

 

[dp004i]

It only happens if I use 1:1 divider, the crad doesn't exhibit any problems whatsoever when OC'ed, as long as the RAM divider is set to 5:4. When I use that, the card runs fine OC'ed regardless of FSB (have it at 270 right now), but when I use 1:1 junk starts appearing at 225FSB. Maybe that HyperX is not so hyper after all. But then again, it looks like some people are having similar problems with Corsair brand PC500 RAM.

 

[Technonut]

What timings and VDIMM were you running @ 1:1?

 

[dp004i]

3-8-4-4, tried all voltages up to 2.8V.

 

[Margalus]

Originally posted by: dp004i
H When I use 5:4 CPU:RAM divider instead of 1:1 divider, everything runs like a champ at 250FSB. My RAM theoretically should be able to handle 250MHz speed,

the problem is your motherboard. You have the i865 chipset, they are speed binned and most won't go very high 1:1, you have to run 5:4. For high 1:1 overclocks you need the i875 chipset. My p4p800 i865 board won't go over 217mhz 1:1 with any memory. But some of that same memory will do 290mhz 1:1 on my p4c800. If you want to stay with abit and get high 1:1 overclocks you need the ic7 i875 board and not the is7 i865 board.

 

[dp004i]

All right, I see. I guess I should've gotten an IC7, but that refurbed $55 IS7-G at newegg was too hard a deal to pass up. Guess that's why it ended up in refurb section in the first place . But then again, the benchmark scores I'm getting at 5:4, 260FSB with tighter memory timings are virtually identical (about 1-2% slower) to those I get at 250, 1:1 and slower timings, so I guess it's not such a big loss after all.

PS: The funny thing is, it runs all benchmarks and prime95 fine at 250fsb, 1:1; ithe only problem is graphics corruption in video games. That's why I can't really understand what's causing the problem in the first place.

 

[Margalus]

graphics corruption is not only a symptom of problems with video memory, it is also a symptom of problems with system memory. And that is exactly what yours is showing.

 

[jdogg707]

I have heard of problems with Abit 865/875 motherboards with Kingston memory, that may be your problem.

 

[nealh]

I am not sure I agree the AntecTrue power supplies are not good for overclocking a P4 ..I would like to see more opinions on this issue

 

[myocardia]

Originally posted by: ectx
Interesting. I am not convinced it is a problem of your ram though. Have you tested your ram using memtest86 (or windows memory tested by ms)?

I always thought video ram oc is the main source of artifacts (gpu oc would produce some slightly different artifacts). I was puzzled as to why I need to reduce oc when I increase fsb. I always thought it is the nb. But what do I know?

ectx, your problems are more than likely psu-related. Anytime you have to reduce a video card's OC to make the cpu become stable, it's because your psu is running out of power. Overclocking requires more power from everything, especially the psu.