Overclocking my P4

M

mut

Geek Trainee
I overclocked my PC today.
Since its a Sony Vaio, I have to shut down, remove the power, remove the RAM, plug in the power, start up, let the system give me a good old error beep, take out the power, put the RAM back in, put the power back in, then press F2. And that gets me into a BIOS where I can actually edit stuff, otherwise I can't really do anything in BIOS (Sony protection i guess).

I have a Pentium 4 Northwood 2.00GHz
Family 15 Model 2 Level 4

I cleaned out my CPU fan (as it had quite a collection of dust bunnies going on), and overclocked it to 120/40 frequency. Giving 2.4GHz.
I also lowered all my RAM's latencies (some are now 4T, some 2T and one is 1T).
The temperature, I am happy to see is less than it was before I overclocked. The cleaning of my CPU fan had quite an impact. I am now idling at 44*C.

I have a question, however:
In your experience and out of your knowledge, would leaving the top of my PC case (where the CPU is) off be a good idea?
 
Well, I need to know more about RAM timings, on full load my system crashes.
I reset the RAM timings to default and it runs fine at 2.50GHz.
 
Ah, now THAT is why i stopped o/c ing, I THINK it is a good idea to get aditional cooling for your RAM, heat spreaders are a good choice, or if you have the room, heatsinks on the ram chips, 8 each side (DDR i assume)
 
Low latencies will not damage your RAM, you just have to reset them if they don't work. When OCing permanent damage is rare. If you RAM can't handle the speed it usually won't work at all.
 
when you O/C your CPU, your RAM goes up 10MHz every 100MHz, I think this is why mine was crashing. I only have value RAM that cost me £30 per 512 with no aditional cooling. I heard about a "divider", whether thats aa program or something I don't know, but it reduces your RAM to keep it low so your PC won't crash with just the CPu getting O/Ced
 
I wouldnt leave the side off the computer for long because it will just fill up with dust even quicker than usual. It depends on your case but it shouldnt be too hard to get a motherbaord temp of less than 30c with some good fans in there.

Heatsinks on RAM are a waste of time IMO. Oh, and lowering your latency untill it crashes is bad especially if your half way through loading windows or something. Its no different than pulling the plug without shutting down first. You can cause permanent damage in that it will become less stable and less reliable. More crashes, blue screens etc.

What stepping revision P4a have you got? CPUz will tell you. If its a B0 then 2.5ghz is pretty well the max. In fact you will be lucky to pass post at anything higher. Thats what I used to hit, it was OK for windows, games etc but it crashed when compiling Linux packages and I since tried Prime 95 which came up with loads of errors. You will be lucky to have 2.5hz which is solid, id go back down to 2.4ghz.

What RAM have you got? If its DDR400 you will probably be best off at 400mhz with lower CAS latency. I reckon the timings make much bigger difference than the frequency its running at. Test the bandwidth of the RAM, IMO thats the biggest advantage of overclocking RAM; helping to reduce bottlenecking.
 
Yeah DDR400 runs at 400mhz. It has to run at 400mhz so it can get 3.2gb/s bandwidth.
Whence DDR400/PC3200.

You must have a FSB of 200mhz which is then doubled to 400mhz.
The P4 2ghz chips have a 100mhz FSB but the processor runs with a bus of 400mhz so the FSB is quad pumped and you get 400mhz on both the CPU and RAM. ie RAM is at a 1:1 ratio.

I said hes best off setting the RAM to 400mhz with the FSB at 120mz (2.4ghz cpu) which means hes setting his motherboards RAM frequency to the ddr333 setting which is then using a different multiple of the FSB ie a different ratio. Overclocked to 120mhz the DDR333 ram will run at 400mhz, which is perfect because that whats his RAM is rated at.

He'll probably come back and say hes got DDR333 now which will make all the number wrong. He'd have to setup his motherboard for DDR266 to get 333mhz and a FSB of 400mhz :)
 
My P4 is B0. It's the same as you have, Zeus.
After having overclocked it to 2.5GHz, I experienced crashing when the CPU usage increased: for example when loading America's Army (PC Game).
I now have it running stable at 2.4GHz.

As for the RAM, I know I shouldn't but I mixed two sticks of RAM, each with a different frequency - I get better performance when I do this (rather than just using 1 stick of RAM), so I stuck with it.

512MB @ DDR400
256MB @ DDR??? - There is no sticker on the RAM, and this came with the PC.
 
zeus said:
Yeah DDR400 runs at 400mhz. It has to run at 400mhz so it can get 3.2gb/s bandwidth.
Whence DDR400/PC3200.

You must have a FSB of 200mhz which is then doubled to 400mhz.
The P4 2ghz chips have a 100mhz FSB but the processor runs with a bus of 400mhz so the FSB is quad pumped and you get 400mhz on both the CPU and RAM. ie RAM is at a 1:1 ratio.

I said hes best off setting the RAM to 400mhz with the FSB at 120mz (2.4ghz cpu) which means hes setting his motherboards RAM frequency to the ddr333 setting which is then using a different multiple of the FSB ie a different ratio. Overclocked to 120mhz the DDR333 ram will run at 400mhz, which is perfect because that whats his RAM is rated at.

He'll probably come back and say hes got DDR333 now which will make all the number wrong. He'd have to setup his motherboard for DDR266 to get 333mhz and a FSB of 400mhz :)
Click to expand...

wat do u mean the DDR333 ram will run at 400mhz, which is perfect because that whats his RAM is rated at. his ram is ddr400 and runs at 400mhz, u cant have a 400mhz ram at ddr333 run at 400mhz wen overclocked or sumthing, it doesnt make sense.
u can set the ratio of the ram for ezample if ur fsb is 200 and origianlly it was 100mhz (unlikely to happen but just an example), then u can set ur ram as 1:2 ratio becoz the ram will run half the speed of the fsb
 
If you have got a 100mhz FSB which is quad pumped and use DDR333 then overclock the FSb to 120mhz then the ratio for the DDR333 will go to 400mhz.
5:3 ratio os for DDR333 on a 100mhz FSB
1:1 ratio is for DDR400 on a 100mhz FSB

100mhz FSB on a 1:1 ratio = DDR400 (2x200mhz)
120mhz FSB on a 1:1 ratio = DDR480 (2x240mhz) DDR400 will probably be unstable.

100mhz FSB on a 5:3 ratio = DDR333 (2x166mhz)
120mhz FSB on a 5:3 ratio = DDR400 (2x200mhz)

So he can use a 120mhz FSB and DDR400 at 400mhz (using the 5:3 ratio) or DDR400 at 480mhz using the 1:1 ratio. I know which ive used for the last 3 years! He must have always been using the DDR333 ratio because he was at 2.5ghz (125mhz FSB) which means his RAM would be at 516mhz!

Its annoying because if the B0 P4a could just hit 2.66ghz then the ratios would be reset and so would the PCI bus, which is getting pretty high itself 120mhz FSB.
 
zeus said:
If you have got a 100mhz FSB which is quad pumped and use DDR333 then overclock the FSb to 120mhz then the ratio for the DDR333 will go to 400mhz.
5:3 ratio os for DDR333 on a 100mhz FSB
1:1 ratio is for DDR400 on a 100mhz FSB

100mhz FSB on a 1:1 ratio = DDR400 (2x200mhz)
120mhz FSB on a 1:1 ratio = DDR480 (2x240mhz) DDR400 will probably be unstable.

100mhz FSB on a 5:3 ratio = DDR333 (2x166mhz)
120mhz FSB on a 5:3 ratio = DDR400 (2x200mhz)

So he can use a 120mhz FSB and DDR400 at 400mhz (using the 5:3 ratio) or DDR400 at 480mhz using the 1:1 ratio. I know which ive used for the last 3 years! He must have always been using the DDR333 ratio because he was at 2.5ghz (125mhz FSB) which means his RAM would be at 516mhz!

Its annoying because if the B0 P4a could just hit 2.66ghz then the ratios would be reset and so would the PCI bus, which is getting pretty high itself 120mhz FSB.
Click to expand...

thx for correcting (or explaining in more detail) it makes sense to me now
 
The Northwood P4 is really good for overclocking, well mine was anyway. I had a 2.4 running at 3.0GHz. I got the FSB to a stable 250 with corsiar value ram cas 2.5.
 
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