PSU Problem on 1.6a overclock

[outsiderGT]

Hey everyone,

I have a setup w/ a P1.6a on a ASUS P4B266-C w/ some Corsair PC2700 DDR memory.... I can OC till about 2.2GHz safely (cpu stays at about 40c)... now when I try to go over 2.2GHz, the system refuses to even post and just gets a consistent beep.

Now, when trying to actually run games (using my GF3 Ti200) on the 2.2GHz overclock, they will run for a short while before simply crashing out and dumping me back into winXP. I have isolated this to be an overclock problem and not a driver issue because it dosent happen when I dont overclock.

What I can conclude of all this, is that my PSU is crap and is not providing enough power to the video card when the cpu is running at a higher speed... could this be the cause? I am using some no-name crap PSU I bought some time ago that I was using on my old P3-800 setup. Its a 300watt unit.

What unit would you guys recommend and do you think this is the answer to my problem?

Thanks for reading

 

[WangButter]

It could be your PSU, or it might be your cpu's temperature. Before you go ahead and plonk down $100 on a new Enermax PSU, however, you should probably try running a motherboard monitoring program like PC Probe to keep track of your CPU temp / voltage. You say your cpu stays at about 40c, but what is its temperature under load? Are you using the stock Intel HSF?

 

[WangButter]

BTW, when I say "under load", I mean you should enable logging on the monitoring program and then try running Prime 95

 

[AnAndAustin]

Whether or not the PSU is the prob I'd def get a new one.

As you suspect unbranded PSUs are of very low quality and VERY often cannot do the quoted W's, certainly without spiking.

Enermax: Good, perhaps slightly over-rated but solid, stable performers. Perhaps a bit pricey.
Antec: Excellent value for money and at least as good as Enermax.
ToPower: Esp 420, 470 & 520W; as good as Enermax but a fair bit cheaper.
SuperFlower: Esp 470 & 550W; very good too (despite the name), may find them rebranded Atlas.

All the above are high quality PSUs and as such some with 2 quiet (and often smart) fans and therefore vent the CPU area, plus HS inside so fans don't have to be so fast/loud. Very quiet, very reliable and very future proof (as much as PC hw get).

A good friend of mine strongly rec Antec 430W, 2xPSU fans are quiet & smart ctrl (adjust speed according to heat) and has conn for case fans to be smart ctrl by PSU too.

Anyway, here's the links for more info:

Antec

Enermax

ToPower

Super-Flower

PS. Be sure to go for a 350-400W PSU, you don't want to have to upgrade simply because you tried to save $10!

 

[Tom]

At 2.2g I would think trying to run vcore too low is more likely the problem than temperature.

What vcore setting are you using and what is the actual vcore reading in the bios ? Sometimes a small increase will improve stability at a given speed.

BTW, it could be a PSU problem but not necessarily. I'm currently running my 1.8a at 2.4gig with 1 hard drive, a CDRW, a DVD drive, and a GeForce3 Ti200 with an Aopen 250w PSU and it is just as stable as it is when I use my 400w PSU. Been running Prime95 for several hours.

 

[AnAndAustin]

I wouldn't expect even a P4A1.6 to get over 2.2 anyway, although I realise many do at least run stabily at this.

PC2700 should get to around 175/350 without probs, although you may have to increase the CL (eg to 2.5-3-3-7) so that shouldn't be a prob, try SiSoft Sandra to check the actual RAM speed when you o/c.

I imagine you're o/c that GF3TI200 (if not then do once stable), but remember increasing the FSB without adjusting the PCI/AGP divider can cause the AGP card to run at higher speeds too, therefore your o/c GF3TI200 which was stable with the CPU at 1.6ghz may not be when it's at 2.2ghz. I'd try setting the GF3TI200 back to defaults and see if that helps the instability.

Remember also that the temp readings on mobos are very approximate and with a reading of 40'C you could be anywhere around 35-45'C. You should use it as rough estimate of how much hotter the CPU is running and not of its actual temp.

Loops of 3Dmark are just as effective at putting your whole PC under load as anything else IMHO.

 

[Duvie]

<<I wouldn't expect even a P4A1.6 to get over 2.2 anyway, although I realise many do at least run stabily at this.>>

Way wrong...MOst if not all get above this...It would be a major disappointment not to at least get this, especially with newer stepping of 1.6a's...At 2.2ghz means you are somewhere around 138fsb so pci/agp should be a none issue. Should also be 1.6v to default at this point...

<<PC2700 should get to around 175/350 without probs, although you may have to increase the CL (eg to 2.5-3-3-7) so that shouldn't be a prob, try SiSoft Sandra to check the actual RAM speed when you o/c.>>

most pc2700 is cas 2.5 but the corsair maybe cas 2...my pc2700 gets currently 205/410 with a voltage boost to 2.6v...It needed that boost rightaround 390mhz ddr...

<<I imagine you're o/c that GF3TI200 (if not then do once stable), but remember increasing the FSB without adjusting the PCI/AGP divider can cause the AGP card to run at higher speeds too, therefore your o/c GF3TI200 which was stable with the CPU at 1.6ghz may not be when it's at 2.2ghz. I'd try setting the GF3TI200 back to defaults and see if that helps the instability.>>

like I mentioned above 2.2ghz on a 1.6a chip is only like 138 and most all boards would revert to a 1/4 pci divider meaning he is running like 34.3mhz pci/ 68.6mhz agp...hardly out of spec for 33 pci/66 agp...my agp is running like 82mhz right now and for the last 10 weeks.

<<Remember also that the temp readings on mobos are very approximate and with a reading of 40'C you could be anywhere around 35-45'C. You should use it as rough estimate of how much hotter the CPU is running and not of its actual temp.>>

could be true...I think you should be worried with like idle temps in the 50's and load in the 60's...otherwise likely not a problem...

<<Loops of 3Dmark are just as effective at putting your whole PC under load as anything else IMHO. >>

I agree, but I have been able to get the pc to fail under prime95 when 3dmark and pcmark failed to crash....I also like a good old divx encoding to stress the system...maybe simultaneously with one of the above mentioned progs...




IMO...

The psu could be the issue, but you need to list for us the actual readings on the different volt rails...both in idle and load conditions

Secondly it is likely it needs a minor vcore boost.

Set ram setting to 1:1 for diagnosis and run system to rule out ram...

 

[AnAndAustin]

Just a quick note on the "68.6mhz agp...hardly out of spec".

AGP 4x runs at 66x4=266mhz. So 68.6x4=274.4mhz and quite understandably this small increase on an already 'at the limit' gfx card could cause instability.

As for your other points;

I'd heard those P4A 1.6ghz o/c like magic (see my post). All your points are of course very valid. I've been using (and recommending to others) AMD for a couple of years now, for great price/perf ratio. BUT NOW the P4's are the clear winners and, as I am unbiased, I am trying to learn more about the P4's. I make PC's for other people as a 'hobby', there's sooooo much info to take in to cater for everyone's tastes .

 

[NanoMem]

OutsiderGT,

Are you feeding all power connectors including aux and EZ plugs on your motherboard?

If you still suspect you PSU is not adequately juicing your P4B266 and/or its components while overclocking, you could try Motherboard Monitor to monitor fluctuations in rail voltages with and without overclocking. If I recall ATX power spec's require rail voltage fluctuations to be less than 5 or 10%. Look up "ATX specification 2.03" on google for details. You might think you're out of spec's while overclocking but the key is to keep vcore at or less than 1.7V (or 1.85V if overvolting cpu). If you decide to go out and buy a new PSU, I recommend ANtec Truepower units due to their strict compliance with these spec's. Compare these spec's for yourself with ones from enermax or sparkle and go with the best one.

RAM overclocking might hold the P4B266/P4B533 back in terms of best performance out there but these boards imho definitly are the best in terms of voltage/heat stability at your level of FSB clocks.

Peace.

 

[Duvie]

<<AGP 4x runs at 66x4=266mhz. So 68.6x4=274.4mhz and quite understandably this small increase on an already 'at the limit' gfx card could cause instability.>>

Yes I am aware of that and turning off 4x to diagnos is also a good option to try to isolate vid card....

However, I think most newer gf2 pro and greater 4xagp cards can handle that with ease....I have had 3 diff vid cards running 82mhzx4 for 328mhz...My GF2 pro Gainward Golden sample, radeon 8500le, GF4 mx 440 Golden Sample...the gainwards I even then ocd the card to high levels...

 

[Barrei]

When you get bumped out of your game back to your homepage that is a classic cpuv problem, you need to up your cpu voltage , try a .25 voltage increase to cpu , run vid card at default settings , and see if you can play your game without getting bumped out , if you can then up your vid card to your preferred overclock settings , play game again , if it will play ,great , if not then up your agp slot voltage .2 volts and try game again.

 

[outsiderGT]

First, thanks for all the replies.

Now, as far as underload, temp seems to go between 43-50, so its not that bad. VCore is currently set a 1.50 (default) havent tried messing with it yet.

The GF3 is currently running stock- for the reasons you stated. I wanted to make sure my CPU was running stable b4 I bumped up the juice on the GF3.

As far as the actual readings on the diff volt rails, I'm going to download Motherboard Monitor as recommended now to check out those readings.

Nanomem: I'm using the ASUS EZ-Plug (in lieu of the ATX12V connector since my PSU dosent have a ATX12V connector) and the standard ATX powersupply, as far as I can tell my MB dosent have an AUX connector.


Also, one more strange thing I noticed... it seems that in games such as JK2 or SoF2, the system kinda lags behind when encoutering enemies or a large object moves around. For example, the system always seems to stutter in JK2 when someone kills me (I will kinda loop my characters death voice till it respawns me) What could be causing this? I'm running at 1024x768, w/ full details.

 

[outsiderGT]

Oh, and I forgot to mention I am using the stock Intel HSF.

 

[AnAndAustin]

The stock Intel HSF is a decent one. It can even handle o/c.

But it's no match for the likes of ThermalTake Volcano 7+ which is not only efficient & reliable but also gives excellent cooling even on the medium setting of its speed control.

Swiftech MCX478 also very good too.

There are lots of excellent coolers out there that don't cost that much, but there are also some crappy ones too. I'd strongly rec either of the above 2. Anybody else got any recs?