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P4 overclocking - As easy as they say?

Yadda — Mon, 06 Jan 2003 12:01:56 GMT

Your welcome matey, glad to be of some help :)

P4 overclocking - As easy as they say?

fidbloke — Sun, 05 Jan 2003 21:34:08 GMT

Yadda - Thanks mate!
That's the sort of basic information I was after when I started this thread.
I just needed a bit of 'how to' info on the subject.
The problem is, that if you look for overclocking info in magazines they tend to say "Woo yeah! there's this fing called overclocking and it makes your computer go faster, WOW!!!", which isn't very helpful!

Thanks.

P4 overclocking - As easy as they say?

Yadda — Sun, 29 Dec 2002 22:44:30 GMT

Most (all?) modernish P4 motherboards have the option to lock the PCI bus speed meaning it is not affected by the FSB. So your PCI, AGP and hard drives will be fine :).

The memory speed will increase - but thats a good thing if you have good memory as the P4 Northwood CPUs can use a LOT of memory bandwidth. If the memory struggles at a certain FSB, the select a lower FSB:MEM speed ratio in the bios.

e.g. My BG7 DDR ram mobo has 3 ratios availible. These are

1:1
4:5
3:4

e.g.if my FSB is 150mhz and i choose:

the 1:1 ratio, my memory will then be running at 150mhz *2 = 300

or

the 4:5 ratio, my memory will then be running at 150 *1.25 *2 = 375

or

the 3:4 ratio, my memory will then be running at 150 *1.33 *2 = 400

So, depending on the speed and quality of ram you have, you select the appropriate divider :)

My Samsung PC2700 (DDR333) ram so should really be using the 1:1 divider at 150mhz FSB, as all the other divides should result in memory speeds to great for this ram. However, It is good ram, and manages to run the 3:4 divider which i'm very pleased about.

P4 overclocking - As easy as they say?

fidbloke — Sun, 29 Dec 2002 19:49:59 GMT

I thought the point of using a 100MHz FSB chip with a big multiplier, was that it could be overclocked to 133MHz for big CPU speeds without pushing any of the other bits (memory, AGP or PCI buses etc.) beyond their normal operating limits. Surely whacking the FSB to 150MHz or more will cause other parts of the system to fall over? I thought that getting a 100MHz chip with a big multiplier would solve this problem and give big CPU speeds of just over 3GHz-ish.

P4 overclocking - As easy as they say?

Yadda — Wed, 25 Dec 2002 02:44:29 GMT

well, my PIV is a 100mhz FSB chip. The standard speed is 100x18 = 1800mhz, i run mine at 150x18 = 2700. Regardless of the CPU's *default* FSB, the higher you can get it (the FSB), the better - becuase the motherboard's system bus speed and DDR memory speed is calculated from the FSB.

e.g.
1) Standard 1.8a CPU.
FSB = 100mhz
motherboard system bus (FSB*4) = 400mhz
DDR ram speed (3:4 FSB:DDR ratio selected) = 133 (x2 = 266mhz DDR)

2) My 1.8a at 2.7Ghz.
FSB = 150mhz
motherboard system bus (FSB*4) = 600mhz
DDR ram speed (3:4 FSB:DDR ratio selected) = 200Mhz (x2 = 400mhz DDR)

3) A typical highly overclocked 1.8a (or 2.4b) C1 stepping PIV at 3.3Ghz.
FSB = 184Mhz!!!
motherboard system bus (FSB*4) = 736Mhz!!!
DDR ram speed (3:4 FSB:DDR ratio selected) = 245Mhz (x2 = 490Mhz DDR)!!!!!

Obviously, the quality of the ram will limit the speed it will reach - there's no point hoping that a strip of generic PC2100 DDR266 ram will run at 400mhz+ :), or even 333mhz for that matter
.
Investing in some expensive PC3500 DDR ram (or PC1066 rimm's if your using a rambus motherboard) is essential if monster memory bandwidth is your goal, otherwise you'll have to reduce the FSB:memory speed ratio and sacrifice some of the bandwidth :).
I'm currently using a Samsung Original single-sided PC2700 DDR333 memory, but it's happily running at DDR400 speeds :). This particular type of Samsung DDR memory is well known for being a very good overclocker.

Ooops sorry, long post , phew - Merry Christmas!!

P4 overclocking - As easy as they say?

marky9876 — Mon, 16 Dec 2002 13:45:32 GMT

Aren't the 100Mhz P4s meant to be better for o/c? - they usually get to 133Mhz without extra cooling

P4 overclocking - As easy as they say?

Yadda — Sat, 14 Dec 2002 03:53:02 GMT

I've got a 1.8a (18x100) running at 2.7 (18x150) :) 50% overclock! It's in a BG7 with some Samsung PC2700 (DDR333) running a 3:4 ratio to the FSB (ie 150:200) therefore operating at DDR400 speeds :).

CPU would run 2.5ghz with 1.60v actual, but needed to be vid-pinned to 1.77v actual to reach 2.7ghz. Will run apps at 2.8ghz but not stable in games. Cooled by an ALPHA 8942, temps 47degC idle, 52degC load.

The new "C1" stepping 2.4b chips are the ones to go for at the moment, most will reach 3ghz at default voltage, or with just a slight increase. Some are reaching 3.3ghz+ :O

The higher FSB/low multiplier "b" Northwoods offer a very noticable performance advantage, especially if you have quality memory to operate at the potentially higher speeds generated by a higher FSB.

P4 overclocking - As easy as they say?

dwgwilliams — Fri, 08 Nov 2002 15:58:26 GMT

Gsteve happy OC'ing :D

P4 overclocking - As easy as they say?

gsteve — Fri, 08 Nov 2002 00:56:57 GMT

im getting a 2.8 intel cpu soon so i will post the results. ive never used intel after p1 tho so will take a bit of getting used to. i think its a 533 nw chip im getting which means i prolly wont get it past 3ghz but nm will pair nicely with an r9700 and 768mb ram

P4 overclocking - As easy as they say?

dwgwilliams — Thu, 07 Nov 2002 15:49:45 GMT

As marky said thats it (i hate repeating people).I dont know much about oc'ing P4 cus i carnt be bothered with Intel.Any way id get a good coller you dont wannna blow a £200+ processor and use a 10 quid cooler, if it fails or carnt cool the p4 you gotta get antother one and will have a nice aroma of melted cpu coming out of your Pc.

P4 overclocking - As easy as they say?

marky9876 — Tue, 29 Oct 2002 15:58:14 GMT

Essentially yeah - most stock fans will take the strain of upped CPUs

P4 overclocking - As easy as they say?

fidbloke — Mon, 28 Oct 2002 00:07:36 GMT

From what I 've seen on various websites, overclocking a Northwood Pentium 4 doesn't look too difficult.
Simply select a 100MHz (400MHz FSB) CPU (bigger clock multipliers than the 533 chips!) and whack the FSB to 133MHz (533MHz).
If the resultant CPU speed is more than 2.5GHz, then increase the CPU core voltage by 25mV to 1.525V to aid system stability.
Lastly you just stick a big heatsink on top and stand back in amazment as your creation chews it's way through any bloatware you care to throw at it.
The thing is, is it really that simple, or have I missed something?[/SIZE]