P4 3.0. How high on air?

Adeptus Titanicus

Yeah, another newbie question.

I'm reading alot about ppl getting 3750 and 3800 on this chip, so I've been ramping it up. I'm on 240 FSB running prime 95 with 1:1 timing on the RAM. I ran prime earlier with the RAM ratio set to Auto (came in at 3:2), and prime ran for an hour and a half before I shut it down to try something higher. Temps got to 49 on the CPU (mobo probe).

What I'm wondering is, what defines the limit? I know that's a bit of an "how long is a piece of string" question, but how long should I test it with something like prime before going to the next level? I am not a patient man

Also I'm bored.. Had to watch Chitty Chitty Bang Bang earlier while running prime.. :rolleyes:

Col_Loki

Also I'm bored.. Had to watch Chitty Chitty Bang Bang earlier while running prime..

lol. U know you can still use your PC while prime95 is running (i didnt at the start). For using the net, playing music its fine!!

Generally your overclock is quite stable if prime runs for 1 hour. Anything close to that and its good to go onto the next step. When you've finished run prime95 for 6-8 hours to make sure its fully stable and your sorted.

Limiting factors lol, there can be alot..... temps, the CPU, the motherboard FSB limit, the Ram, the PSU. You seem to be doing pretty well at the min 3.6ghz isint bad. Try to keep the memory and FSB at 1:1 for aslong as you can (loosen the timings mabye and up the Vdimm voltage).
unkel got his up to 3.8ghz with a simular setup (same cooler and chip but Pc4200 ram).

Your temps are fine, the coolers doing its job, your PSU should be perfect, motherboard should hit 250mhz FSB+ (thats a should), Ram with looser timings and higher Vdimm ~ 250mhz mabye more......... you want as little limiting you as possible and youve done a good job with that ....... only thing now is to keep her going and see how well it does.

Good luck

Adeptus Titanicus

hehehe... Yeah, I was using it while running prime, but found it a little crawly. Like I said, I'm not patient So I dragged out the work laptop and surfed/researched a bit. Actually, hadn't seen that movie since I was a kid and the G/F had never seen it (German) so that's my excuse and I'm sticking to it!

Thanks for the encouragement. I feel it's going ok, but I get worried about the timings. I seem to recall manually dropping the timings yesterday (2,3,3,7) and the rig wouldn't POST. Are there any "rules" about what combinations go together or is a "suck 'em and see"? I definitely got a boost from overriding the auto to 2.5-3-3-7, but I got a couple of errors in Prime, and that was with an FSB of 233! I'll try it again to be sure...

Think I'll go and look for unkels sig or setup...

Thanks again!

Woden

ram can be a bit fun sometimes i think, my ram is rated for 2-3-3-7 which is fine, so when i went to overclock i though right i'll slacken the timings something like
2.5-4-4-8 or 3-4-4-8 and iirc it won't post, apparently the winbond on my chips doesn't like high cas 2.5 or 3.0.

with regards to timings leave em slack and find the best fsb you can get using prime, then when you have that you can start tightening the timings again running prime, when the timings get too tight prime will start lashing out errors.

something else you can to perhaps quickly test if ram timings are gonna coz you issues is pifast, check it out on www.hexus.net, i found that if the memory is acting up try to run pifast and it may tell ya straight away, anywho there is articles knocking around recently about how ram timings don't seem that important anymore, best get the highest fsb you can without the ram hindering ya and then ya can worry about it.

data

Adeptus Titanicus

Yeah, I'm basically following the principles I follow when debugging code or a system. Change one thing at a time, so like you say Data, I'm aiming to find the fastest FSB I can first, then begin on the RAM proper. I've just now begun dropping the vCore while at 240 to see what happens, mainly to see what happens to temps, but it's holding stable too. I had set it to 1.6 in the BIOS, so now I dropped it to 1.55 (temp dropped from 49 to 45 running prime). The funny thing is that CPU-Z shows that the vCore actually drops while running Prime. It's at 1.488 now.


I'll certainly try PiFast. I had seen it on some other sites, so it's good to know what it's good for. Thanks for the tip.

I'll probably have more questions on RAM timings when I start to break things.

Cheers Guys!

Woden

hmm is cpuz at 1.55vcore and then when you turn on prime95 it drops to 1.488?

i'm not sure how accurate that is but it won't be a fantastic sign would indicate to me that underload your psu can't supply the vcore its meant to the chip, anyone feel free to correct me here.

what piece of software monitors your 12 and 5 volt rails and such, do these change much when you go from idle to load.

for example my rails don't change when i switch on prime95 which is a good think, my vcore fluctuates 1.71-1.73 roughly all the time regardless of load or whatever, which is expected i think as the abit board undervolts.

with regards to you overclock if you are only putting 1.488 volts through you cpu at load and its prime 95 stable its good that you have an overclock stable at that voltage instead of the higher one but consistant voltages would be better.

anywho pick a vcore your happy to maintain and keep increasing the fsb until prime crashes after something like 30secs, with loose ram timings and a decent vdimm you'll pretty much know you've meet or exceeded you fsb limit especially if the ram you have is rated for that frequency (if its not it could be time to start messing with the dividers). when you find this point start dropping the fsb down a few megahertz until you get a stable overclock.

imo i prefare to find my limit and drop back then have to keep doing a large series of tests everytime you up the fsb a wee bit

Adeptus Titanicus

Originally posted by Dataisgod
what piece of software monitors your 12 and 5 volt rails and such, do these change much when you go from idle to load..

anywho pick a vcore your happy to maintain and keep increasing the fsb until prime crashes after something like 30secs, with loose ram timings and a decent vdimm you'll pretty much know you've meet or exceeded you fsb limit especially if the ram you have is rated for that frequency (if its not it could be time to start messing with the dividers). when you find this point start dropping the fsb down a few megahertz until you get a stable overclock.

imo i prefare to find my limit and drop back then have to keep doing a large series of tests everytime you up the fsb a wee bit

I'm using the Asus Probe that came with the mobo. I seemed to be getting spikes last week on the 5 rail, but it's been rock solid since I flashed the BIOS. I don't notice any swings on any of the rails going from idle to load and vice versa. I'm recording al log, so I can look back over it.

I hear ya when you say find an upper limit then dropback. I'm jumping in 10's and 20's, not in smaller increments. Just went to 250 and XP locked up. Trying a few things out now to see what's up... Could the memory beng at 1:1 at this FSB cause this being 3700?

Edit:
Forgot to mention I had used MBM 5 last week when checking out the rails. Will take a look at it again.

Sir Random

The P4C800 is well known for the voltage droop on the vcore, don't worry about that.
You shouldn't really touch the vcore until you hit the cpu's limit at stock. This way, you'll know when your cpu is approaching it's max, as it demands more and more juice. It's best to leave the ram at 3:2 until you find the cpu's limit, so it won't mess up prime95 tests.

Woden

sir random does that voltage drop actually occur then or is it just reported as occuring?

Adeptus Titanicus

Yeah, I was thinking it was a "feature" of the board. Have seen lots of comments about it in other forums, so at least I knew it wasn't unusual for the board. I just wonder does it affect stability.

Anyhow, I can't seem to get stability at 250, but am trying!

Sir Random, will follow that advice and let the memory stay at 3:2 for the moment while upping the core. XP just froze again, so I wonder what I should up next... Will up the vCore and see what happens...
:rolleyes:

Col_Loki

Possibly up the chipset voltage a notch, might help a little.

250mhz FSB would be pretty nice , just a tad off 3.8ghz ....... even 240mhz FSB isint bad going. Shape'n up nicely keep us informed.

Adeptus Titanicus

Well, I think I've cracked the mofo (as opposed to the mobo ). FSB at 250, Core Speed 3750MHz. Upped the vCore to 1.7v and have had Prime running for about 30-45 mins. All systems go! Will run it for a few hours to see how it fares. CPU temp maxing at 51 with the fans up full. Up to now XP locked up after running Prime for about 5 mins.

Still get the vCore variations, but I guess upping the "reference" vCore gave the buffer required. While running prime, CPU-Z showed the vCore dropped as low as 1.55v. Am I worried? Hell No!

Memory is at 3:2 2.5-4-4-8, so will have to do something about that. What do ya's reckon, will the 3700 run happily at that FSB at 1:1? Time will tell anyway .

Sir Random

Very nice o/c!
You're a braver man than me, I haven't gone past 1.65v on the core and I only did that once to get to 4Ghz. You'll be really flying if the ram does 500Mhz, good luck with it.

Adeptus Titanicus

Time told allright. Bloody thing froze up just now... Grrrrrrrr :mad:

It got alot further than before. Temp definitely isn't a problem as it was pretty stable at 50C. Got as far as Test 3 of the 896K FFT Length test. Is it worth upping the vCore beyond 1.7? Going for 248 for the hell of it...

Edit:
Ehhh... OK, from your post Sir Random maybe I'd better not go beyond 1.7? Are temps the only problem with upping the vCore?

Col_Loki

TBH id watch the voltage, its fine on AMD's but 1.7v is a bit dodgy on the intels.

There have been a few cases of processors just giving up at high voltages (northwood P4's). I wouldnt go over 1.7v. Nice work all the same, 248mhz will prob work for you as the fact that prime95 is running for 20mins is a good indication !!

Adeptus Titanicus

Thanks Guys. Enjoying trying all this out. It helps to get the comments too, to keep me on the straight and narrow. Man, a few more beers and I'd up the vCore to 2 or something

Col_Loki

lol, ive done that!! Along with trying my Xp2500+ @ 3ghz..... i really shouldnt switch it on when im home from the pub.

Just as a btw, i found that a system stall when using prime95 was mainly due to FSB problems while Ram & CPU show up errors. Thats just what ive found and is in no way set in stone or anything .

PS did you try upping the Chipset voltage a notch?

Adeptus Titanicus

Originally posted by COL_LOKI
lol, ive done that!! Along with trying my Xp2500+ @ 3ghz..... i really shouldnt switch it on when im home from the pub.

Just as a btw, i found that a system stall when using prime95 was mainly due to FSB problems while Ram & CPU show up errors. Thats just what ive found and is in no way set in stone or anything .

PS did you try upping the Chipset voltage a notch?

Yeah, don't drink and overclock... Think we should set up a points system?

30 mins on Prime at 248 @ 1.7v.

Loki, when you say the chipset voltage, do you mean the CPU vCore? I have the RAM at 2.85, the max the mobo will allow. THe RAM is rated for 3.0 without invalidating the warrenty, so I thought I;d up it to the max to take it out of the equation...

Glad the Blues Brothers is on TV..

Col_Loki

Nope theres a chipset voltage (options should be 1.5v, 1.6v, 1.7v) ........ doh actually come to think of it that mightnt be in your BIOS. Its an option on the abit boards but might not be on the Asus ones!!

248mhz FSB is a very nice overclock, just over 3.7ghz.......... cant really complain about that. Your Ram will be doing well to stay at 2.5-4-4-8 as all the Pc4000 ram i know of either has 2.5-4-4-8 or 3-4-4-8 timings.

Adeptus Titanicus

ahh.. ok, the voltages you quote there sound like what the BIOS lists as the AGP VDDT voltage (or something close to that). The options range from 1.5, 1.6, 1.7 to 1.8 as I recall. I did try upping this earlier to 1.7 when I had the vCore at 1.525 and the FSB at 250 kept freezing, but it didn;t do anything for me at the time, so i dropped it back to 1.5 (default). After all that, is this what you meant anyway?

It's now further than last time, but to be honest I'd be very happy with a 3.6 O/C if I can get the memory tight with the FSB. Think I'll drop it to 3.6 and bring the RAM to 1:1 at 2.5-3-3-7 and run it overnight.

Col_Loki

The voltages are very simular to the AGP but you dont want to go near that voltage....... thats for your graphics card slot (not the actual core so it wont help overclocking).

It must not be an option in your BIOS..... dont know why asus dont include it!!

Adeptus Titanicus

At this stage, although I've been in there so many times tonight, I can't remember the other options. I'll have a look next time I'm in and see if there's anything similar to what you describe.

Still going on the prime at 248!

Bet I've jinxed it now... :rolleyes:

Col_Loki

Hopefully it'l work out for you. Sure give us a post when you know........ ohh and include benchmarks!!

Adeptus Titanicus

Well, couldn't get it stable at 248 with the RAM at 1:1 2.5-4-4-8. So I guess I can say my RAM is limiting me at the moment, as the CPU seems to be happy at 250 with a higher vCore. Going from a ratio of 3:2 to 1:1 locks it up after a while. I could probably go a little higher, but won't for the moment. There's no point if it can only run the RAM at 3:2. I'll try 5:4 later on.

Anyhow, my latest best stable FSB with memory at 1:1 2.5-3-3-7 is an FSB of 240. Have run Prime for an hour minimum on these. Will run overnight to be sure of the higher one. And now for the benchmarks

3.0GHz 1:1 2.5-3-3-6 (SPD), GFX at stock (for reference)
3DMark2001: 17,815
3DMark2003: 5,820
AquaMark03: 43,442
Notes: The SPD settings for the RAM are odd. Originally they were at 2.5-4-4-8 with SPD, but when I went back to SPD settings after manually setting for the overclocks they got set to 2.5-3-3-6. Gave me an extra 400 3D01 and 33 3D03 marks (wow). Might try this on a higher FSB

3.6GHz 1:1 2.5-4-4-8 (SPD), GFX at stock (378/337)
3DMark2001: 19,334
3DMark2003: 5,947
AquaMark03: 45,063

3.6GHz 1:1 2.5-3-3-7, GFX at stock (378/337)
3DMark2001: 19,601
3DMark2003: 5,959
AquaMark03: 45,253
Notes: 1st run od 2001 locked up, CPU got v hot after it locked, so I dropped the vCore from 1.6 to 1.525 to keep temps down a little. Seemed to work. Don't think temps caused the problem in the first place, more like they were a side-effect of the CPU going into some kinda loop internally.

3.6GHz 1:1 2.5-3-3-7, GFX at 414/365
3DMark2001: 20,601
3DMark2003: 6,421
AquaMark03: 48,777


I'll take the 9800 up to XT levels if I can after I get my hands on that VGA cooler. Can't get to Blanch today so might order online. Might get some fancy bits from Jes at the same time...

Would really like to break that 250 FSB barrier, so I'll test the 5:4, and with any luck will be able to benchmark it for the hell of it. Any ideas about timings that might help?

Col_Loki

Thats not bad at all, breaking the 20k mark in 2001......... nice.

To do with the memory you could set it to 3-4-4-8 and see if that stabilises you, generally those are the stock timings on Pc4000 and Pc4200 Ram.

Cyrus

Adepteus, just wanted to point out, to ascertain proper stability with a hyperthreading p4 you need to run 2 instances of prime or prime and another stabulity tester, if u just run prime 95 on its own u'll see the processor is only at 50% load.

Also there arent that many useable voltages on the asus p4c800, goto www.asusboards.com and to the forums and intel chipsets and u'll see loads of posts realting to the voltages.

Basically 1.5875 is the most stable voltage under 1.7v and anything from 1.6-1.1675 is useless, dunno bout 1.7 tho never tried that high

Finally i have a 3.0c on a p4p800 and its prime stable (two instances ) at 3.53ghz 1.5875v if thats any help

Adeptus Titanicus

Ahhh... OK, thanks Cyrus, that's a great tip on the voltages. I went back to 1.7 to try looser memory timings at 250 FSB but all hell broke loose. The thing froze, but what was really scary was the fan controller (an independant piece of hardware) also locked up so all my fans stopped! Man... Had to quickly unplug it all and connect the CPU fan to the mobo to get some air moving accross it. It's all back normal again luckily.....

I have it at 3.6GHz at 1.525v and it's been very solid so far (was quite pleased about that on a low voltage). I'll try the two instances of prime for a longer period on this and see how we go, but I may try for a highrer FSB agai n 1.5875. I'll browse that Asus board and see if I can drag out any more info.

Re Prime, yes I noticed it was basically just using 50%. I tried running a second instance but it didn't start. Maybe I was butter-fingering the mouse... excuse the possible double-entendres there

BTW, What memory and cooling are you using?

Many thanks! All tips/comments greatly appreciated!

Cyrus

to get it tp run twice u need to change the exe name to some thing like prime95-1.exe or something? do a google i cant remember how i did it sorry (you could also use something like toast or pi fast or something, ypu just want to make sure the cpu is being utilised 100%

I have a the all copper version of your cooler and i have half a gig of adata pc4000 ram obviously running at 1:1 its wasted running at 234 fsb tho as it hates tight timings will do 265fsb 1:1 tho so im looking for a good 2.6/2.8

For further info i have a black coolermaster wavemaster with 2 80mm intakes and one 80mm exhaust (all 7v) and an artic cooler on my 9800 (flashed to pro @ xt speeds (barely)

Changing my antec 350w psu for a tagan 380w as the antec is too loud

oh and i have modded the bios on my board so that it runs with pat enabled (ie i get i875 perf from an i865 mobo)

Adeptus Titanicus

Nice setup

I've ordered the VGA Cooler, so I'm lookin forward to seeing what that does for me. You could consider the be-quiet PSUs. They're pretty quiet. The 9800 is the loudest thing in my system at the moment, and it drowns out the PSU... :dunno:

I was considering selling the RAM and getting PC4000, but don't know if it's worth it. I just bought the 3700 as I didn't think I'd O/C all that much..

Will try copying/renaming the Prime exe when I get home. Work always gets in the way of these things.... :rolleyes:

Hellrazer

Stupid question time----When you lot say the ram is running at 234fsb,256fsb etc What do you mean?Im assuming its 234 by 2(DDR)
Was just wondering because at the post screen on my setup its reporting the ram frequency as 300mhz which I assume is the ddr speed since Im running the fsb at 150mhz.
Does this mean that Ive a few more mhz to play around with?
Richie

unkel

Originally posted by Hellrazer
Does this mean that Ive a few more mhz to play around with?

What system do you have Ritchie? If you need some help with your overclock, you'd better post in a new thread

On the Pentium 4 c: FSB 250 (with cpu:ram as 1:1) meams the ram runs at 500MHz (DOUBLE data rate, DDR) and the system is QUADpumped so the bus runs at 1000MHz