prime95 may not catch all oc'ed related errors (updated)

[OS]

I've been playing with my new xp1700/8rda+. In many overclocked configurations, it will run prime95 overnite np.

However, while running prime95 in the background AND using my winmodem, it will freeze. It's not ram related because it will still happen even when running the ram at or below spec (crucial pc2100). It does not do this when the cpu is running stock speeds. My only explanation is that the winmodem utilizes some rarely used parts of the cpu.

I think I've sinced solved the problem by giving the cpu more voltage over what ran prime95 overnite. It runs prime95 for as long as I am using my modem now.

 

[Duvie]

Originally posted by: OS
I've been playing with my new xp1700/8rda+. In many overclocked configurations, it will run prime95 overnite np.

However, while running prime95 in the background AND using my winmodem, it will freeze. It's not ram related because it will still happen even when running the ram at or below spec (crucial pc2100). It does not do this when the cpu is running stock speeds. My only explanation is that the winmodem utilizes some rarely used parts of the cpu.

I think I've sinced solved the problem by giving the cpu more voltage over what ran prime95 overnite. It runs prime95 for as long as I am using my modem now.

that sounds weird!!! I can't imagine what part of the cpu that the winmodem uses that prime95 would not have function to...It is more likely the board is drawing more power while running the device and thus the vcore may drop a notch further and cause it to error. I have yet to ever see that, but that is why many say to run prime95 in conjunction with 3dmark with taxes the next biggest power hog the vid card as well as run separate test on memory....

I bet it is a voltage thing...Run it and watch the vcore, +5v, and +12v without the winmoden and then run the winmodem and watch them together. It is likely the mobos fault and not the cpu at all...

 

[THUGSROOK]

maybe its just the winmodem?

would be worth it to replace it.

 

[OS]

Ok testing the voltage/power theory

modem load

no modem load

I didn't find any appreciable difference in voltages. I guess that's not terribly surprising, I'm using a 431 watt enermax.

 

[OS]

Originally posted by: THUGSROOK
maybe its just the winmodem?

would be worth it to replace it.

I thought about that, but the winmodem seems to work fine when the cpu is not overclocked.

I was thinking about bypassing the problem by using a hardware external problem, but I realized instability is instability, best to try to fix it instead of sweeping it under the rug.

 

[THUGSROOK]

hey ~ save yourself some trouble and ditch the modem

it itself my be causing the instability and there may be no way to fix that.

get a hardware based pci modem

 

[THUGSROOK]

ok ~ well maybe you could try the modem in another pci slot?

 

[OS]

Ok, well I've been on the net and running prime95 for an hour now. In the conditions mentioned below, it never made it past 15 minutes w/o a crash. I'm pretty sure something slipped pass prime95.

 

[SinfulWeeper]

I agree with Thugs. Replace the POS modem.

My father owns an ISP and I have seen one thing consistant. USR makes the best performing external modems, however their PCI versions bite the bullet big time... At least under Win9x, 2K, and linux. We have not tried XP yet as we do not have, and will not get an XP platform.

Intel makes a PCI win-modem that is better than your average win-modem. It uses a chipset which I believe is called HaM. Anyway a hardware modem has three controllers on it. A win-modem has one (and a cheap one at it). In Intels case it uses two. While I was running prime95 and/or SoB while surfing the net, I experienced no stalling... but the machine was not OC'ed like yours.
However it is still a win-modem and uses some CPU. Everyone calls them hardware modems even though they are not. But in any case you can pick one up new off of fleabay for very little money. Just do a search for 'pci hardware' (without the ').

But your best bet is a full fledged external hardware one. Serial types work better than USB, but if serial is not an option... then USB is your only bet.

 

[OS]

Originally posted by: SinfulWeeper
I agree with Thugs. Replace the POS modem.

My father owns an ISP and I have seen one thing consistant. USR makes the best performing external modems, however their PCI versions bite the bullet big time... At least under Win9x, 2K, and linux. We have not tried XP yet as we do not have, and will not get an XP platform.

Intel makes a PCI win-modem that is better than your average win-modem. It uses a chipset which I believe is called HaM. Anyway a hardware modem has three controllers on it. A win-modem has one (and a cheap one at it). In Intels case it uses two. While I was running prime95 and/or SoB while surfing the net, I experienced no stalling... but the machine was not OC'ed like yours.
However it is still a win-modem and uses some CPU. Everyone calls them hardware modems even though they are not. But in any case you can pick one up new off of fleabay for very little money. Just do a search for 'pci hardware' (without the ').

But your best bet is a full fledged external hardware one. Serial types work better than USB, but if serial is not an option... then USB is your only bet.

ugh, like I said, the problem seems to disappear when I stop overclocking.

 

[Thor86]

Umm, well then don't overclock.

Or as others said, get rid of that POS Winmodems. Can't stand them either.

 

[Duvie]

OS, I can see your point....anyway you look at cpu, mobo, whatever is still took more voltage to gain stability...

However remember that prime95 also stresses the memory subsystem and the memory chipset and it may be picking up an derror handling through the pci bus...

As for pirme95 and loading the cpu....Prime95 if the sole program running will load and stress 100% of the cpu. If let run long enough it should stress every realm of the cpu. When prime is ran in conjunction with another app the load is still 100% but now prime 95 being low priority by default will give up the percentage necessary for the other device to operate. I highly doubt the winmodem which is offloading its work to the cpu is having it do more complex things then solving prime numbers. This is why ppl here are perplexed but mainly saying it is unlikely this is the result of a shortcoming of the cpu but instead it is some other part of the motherboard subsystem...

Does the winmodem share an irq with anything??? Don't tell me about winxp cause I run it and with apic enabled in the bios you get irq's up to 21 and I don't have anything sharing. Consult motherboard manual and see which pci slot you can use to avoid sharing with usb devices, and video card...

 

[OS]

Originally posted by: Duvie
OS, I can see your point....anyway you look at cpu, mobo, whatever is still took more voltage to gain stability...

However remember that prime95 also stresses the memory subsystem and the memory chipset and it may be picking up an derror handling through the pci bus...

As for pirme95 and loading the cpu....Prime95 if the sole program running will load and stress 100% of the cpu. If let run long enough it should stress every realm of the cpu. When prime is ran in conjunction with another app the load is still 100% but now prime 95 being low priority by default will give up the percentage necessary for the other device to operate. I highly doubt the winmodem which is offloading its work to the cpu is having it do more complex things then solving prime numbers. This is why ppl here are perplexed but mainly saying it is unlikely this is the result of a shortcoming of the cpu but instead it is some other part of the motherboard subsystem...

Does the winmodem share an irq with anything??? Don't tell me about winxp cause I run it and with apic enabled in the bios you get irq's up to 21 and I don't have anything sharing. Consult motherboard manual and see which pci slot you can use to avoid sharing with usb devices, and video card...

K, well I just checked and it's not sharing irqs

Also supposedly my mobo has a freq locked PCI.

 

[KF]

I tend to doubt the Winmodem is stressing the CPU, but...

Winmodems may have the CPU do DSP = Digital Signal Processing instead of having an on-board DSP. MMX was designed to to do DSP, if I recall. I doubt that Prime95 uses MMX, but maybe the Winmodem driver does.

There are parts of the CPU that Prime95 may not stress completely. The Athlon has so many buffers they are overkill, and probably are not used to full depth except in peculiar circumstances.

 

[Duvie]

go ahead and loop 3dmark...run some divx encoding...open tons of apps...if it is stable then I would look at getting rid of the winmodem...Look at the v92 modemblaster by creative...It appears to be a hardware modem.


I think this could still be more of a sign of the motherboards deficiencies. Maybe it has something to do with devices offloading through the pci bus to the northbridge and onto the cpu. If you had a soundcard it likely has its own chipset and thus doesn't offload anything. Most other devices are not going to do it. Maybe an agp capturing and encoding on the fly liek an ati AIW card which lacks hardware encoder and thus all software and cpu handle the encoding...try that...

If it turns out to be just isolated to the winmodem I would gladly get rid of 15-20 bucks to get higher speed at lower vcore...means maybe a higher overall speed if you stress it a bit more...

 

[zephyrprime]

Your winmodem probably uses MMX or SSE. Prime95 probably doesn't. Prime95 is overrated. Can you try CPUBurn and see if it detects the problem?

 

[OS]

Ok it seems like running 3dmark and prime95 at the same time caused errors in prime 95, in configurations that were previously stable in just prime95 overnite runs.

 

[glugglug]

Prime95 I would wager uses no FPU operations (why would you have any non-integer math to find primes?)

The winmodem is probably heavily FPU dependent.

Most likely if that is the cause video recompression will crash too.

 

[Noid]

I agree ... Prime95 does NOT catch all problems ...
even ran 3dMark at same time ... (benchmark 1 loop)
also ran memtest86 overnite

I ran Prime95 for 3 or 4 days non-stopped .. non-errored ...

.....yet I still had BSOD's appear after I finished testing

Try running Prime95 and 3dMark looped on DEMO NON-DEFUALT settings with SOUND ON ... overnite (12hours)

I havent had anymore BSOD since I passed that test.

 

[rogue1979]

I use a winmodem and found that the ultimate test is running Prime95 and surfing at the same time. When my machine passes Prime95 stable, and then I initialize the modem, it can error out. Lowering my speed a notch or two remedies this error. My only conclusion is the computer is not absolutely 100% stable unless it can do both.

 

[KF]

>Prime95 I would wager uses no FPU operations (why would you have any non-integer math to find primes?)

Prime95 is probably the most FPU intensive application commonly available. It flogs the FPU mercilessly. It uses a sophisticated multiplication algorithm for massively large numbers which cuts down the multiplication time so drastically it become practical to do the prime testing. Before the numbers are multiplied, they are "tranformed", which involves floating point. After they are transformed, calculating the transform of what would be the product is very simple and quick. The result is then tranformed back to get the true product.


You may ask why all this multiplication, when in order to test for primality you have to divide? No, the numbers tested do not need to be checked for divisors in order to prove primality. You can determine it is not a prime without ever finding a divisor. Finding a divisor is much more difficult. It is all very interesting, mind boggling, and mind numbing.

 

[OS]

Originally posted by: rogue1979
I use a winmodem and found that the ultimate test is running Prime95 and surfing at the same time. When my machine passes Prime95 stable, and then I initialize the modem, it can error out. Lowering my speed a notch or two remedies this error. My only conclusion is the computer is not absolutely 100% stable unless it can do both.

Wow, so it's not just me then? I guess my theory kind of works. . .

 

[GUN]

Winmodems just suck.
It's a software modem and needs to run close to the standard 33 mhz pci bus speed. As you know, when you up your fsb, your pci bus speed also increases.
It's also much slower than a hardware modem. Back in the 56k days, I can recall having my CS ping drop from 240 to 120ms after dumping my expensive USR Winmodem for a hardware modem.

As for prime NOT using the FPU....good grief man ? Never just assume, it's dangerous !
It also uses MMX SSE & SSE2 if available.

If your machine can pass Prime95 it means the memory-cpu link is solid. It will tell you nothing about any pci devices, and that includes hard drives, that are not used at the time of testing.
The limit to any overclocked system is usually some bad pci device.

Prime95 is an essential test, but not the only one.

 

[BigJ]

Originally posted by: GUN
Winmodems just suck.
It's a software modem and needs to run close to the standard 33 mhz pci bus speed. As you know, when you up your fsb, your pci bus speed also increases.
It's also much slower than a hardware modem. Back in the 56k days, I can recall having my CS ping drop from 240 to 120ms after dumping my expensive USR Winmodem for a hardware modem.

As for prime NOT using the FPU....good grief man ? Never just assume, it's dangerous !
It also uses MMX SSE & SSE2 if available.

If your machine can pass Prime95 it means the memory-cpu link is solid. It will tell you nothing about any pci devices, and that includes hard drives, that are not used at the time of testing.
The limit to any overclocked system is usually some bad pci device.

Prime95 is an essential test, but not the only one.

8RDA+ is PCI/AGP locked.

 

[GUN]

Lucky !
Ok well then the sofware algorithms must make use of cpu timings and at some stage compare them to your locked 33 mhz pci bus and bingo, your error...or something like that.

Point remains, Winmodem is like a swear word for overclockers and online gamers.