Overclocking Pentium 4 540 - no change?!
Since my Super Pi 1M results on 3.2GHz Pentium 4 540 are somewhat disappointing 45.172 - 44.157sec:
http://s7.postimg.org/65cxk0vef/Supe..._45_172sec.jpg ... http://s17.postimg.org/gbqo51h2j/Sup..._44_157sec.jpg
So then I tried to overclock it a little. It is 200x16 = 3200MHz by default. The only one CPU tweak the MSI PM8M3-V mobo offer is the - after I unclocked it in the bios - FSB. 210MHz FSB post, yet failed to boot into Windows 2000 SP4, claiming that ACPI fail. Lol. 208MHz worked, booted and run SuperPi and CPU-Z validations:
CPU-Z Validator 3.1
CPU-Z Validator 3.1
So, a 3328MHz compared to 3200MHz = I hoped to gain something. But the SuperPi result was disapointingly low - 44.078sec...!!!
So, all the overclocking get me from 44.157sec to 44.078sec :o
I know that this is just a little 104% overclock, but 4% from 44.157sec is 1,76628 sec - and that I hoped to gain. Instead I gained 0,079 sec.
Hmmm. This is disproportional. Anyone can explain me this, or WTF is going on?!
Honestly I wouldn't expect much from a small overclock on an old CPU. Nothing scales perfectly either. You almost always require a much greater increase in frequency % than what a specific program will increase in performance in %.
Netburst was a notoriously poor performer in SuperPi anyway. It takes kinda a lot to make much of a dent in performance. Having said that, the LGA775 P4's tended to have a fair bit of overclocking headroom - so I'm a bit surprised that you were able to get so little out of it at stock volts.
Not perfectly as the clock get higher, but at least remotely close reassembling the incrase in clock.
There should not be a 22,6 difference between increased Mhz and decreased time. It just does not make slight sense to me.
Dead Things -
The increase is indeed laughably small. Rams was tested at 216MHz with tight timings some time ago and should not have a problem at 210MHz. The poor overclock might also have something to do with the AGP/PCI clocks being tied to the FSB, IIRC. Definitively there is no way to set them or lock them.
It was just a attempt to check out, how much I can overclock and how much this will change the SuperPi performance. For serious P4 overclocking it would need a good P4 LGA 775 mainboard. I was just playing there, during experimenting with another mobo that used to run stable at relative high overclocks and now it did not give a go at all...
So I sort of hoped that someone have similar experience or not increasing performance in SuperPi on the Presscot CPUs, so it can tell me that this is normal, because it just did not feel right to me.
Put a 208MHz FSB and got the ACPI bios failure BSOD during booting.
Put a 206MHz FSB and got it working fine:
3.5GHz is the most it can do:
CPU-Z Validator 3.1
trodas`s CPU Frequency score: 3500 mhz with a Pentium 4 3.4 GHz Prescott
Therefore by another independent CPU it is verified, that the FSB increases there could be only very slight :thumb: It makes me wonder, if using Pentium 4 670 (3.8GHz chip) would even allow me any overclocking. Perhaps 2MHz FSB up...? :haha:
For overclocking LGA 775 chips - I got a collection now, lol:
...is necessary to use some respectable board, like Asus P5E64 WS Evolution one:
ASUS P5E64 WS Evolution(X48) mini Review
That, combined with good cooling and perhaps even IHS removal, will allow some serious overclock :thumb:
The MSI PM8M3-V is really a low-end mobo, happy to even work at such speeds, IMHO.
Looks like the minimum gain in SuperPi is somewhat typical for P4:
Because I see absolutely minimal gain from Pentium 4 540 at 3.2GHz 1MB L2: 48.45.890 to 48.04.047 with Pentium 4 650 at 3.4GHz 2MB L2 :( Suxx!
Twice the L2 and 200MHz more for what? 41sec in 48min times?! WTF!
It's been an awfully long time, but IIRC super pi performance back in the P4 days was strongly influenced by memory and bus speeds as well cpu clock speeds. Any chance your OC has negatively affected either of those?
DDR2 and memory speeds are definitely the problem. I remember slapping P4's around with my 3200+ back in the day running OCZ VX ram. I had that stuff running 277MHz CAS2, with 4.1V of course, LOL!
P4 540 - 128MHz more (200x16 to 208x16) = 0.079sec gained at SuperPi 1M test
P4 650 - 200MHz more over 540 (200x17) + L2 (44.157 to 41.297) = 3sec gain at SuperPi 1M test
P4 650 - 200MHz more over 540 (200x17) + L2 (48min 45.890 to 48min 04.047) = 41sec gain at SuperPi 32M test
Looks like the 1M test is way more affected by the ram itself that the 32M test, so therefore there is more noticable (%) gain. But when overclocking the P4 650, the results will be likely similary minimal gains on performance...
I looking for some ram for my S939 rig, about 2x1024 so I can have it for normal usage, when I make it work... and of course I would like if it can be clocked faster that 200MHz default... In fact, I having some settings problems and if you check there:
I go to the 4th place by running rams at only 200MHz and 2,5-3-3-7, witch is nothing exactly fast... :sad:
64.7 points before (200x17), 70.6 points after (206x17) - I see a notable increase of performance! FSB overclocking rulez :D
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