which p4 should i get?

[ryko]

I have 1gb geil ultra pc4400, but i need an excellent overclocking cpu to go with it. My current 2.8c will do no more than 3.5ghz (ddr500/fsb250 X 4 = 1000).

Should i get a 2.4a (533fsb, no HT, 1mb L2---$124), 2.4c (800fsb, HT, 512 L2---$169), or 2.6c (800fsb, HT, 512 L2---$171)?

Anybody have any experience with these cpu's and uber-fast memory? Maybe it is something else holding back my oc? Would water-cooling allow me to reach the coveted 1100mhz fsb?

[ryko]

maybe this should be moved into overclocking forum?

[madmat]

I'd suggest going for a 2.6c or 2.8e for major OC headroom if your setup can deal with the heat of the Prescott.

[keto]

I think the lack of replies is primarily due to the fact that there are no guarantees when it comes to overclocking. 3.5GHz is roughly the upper limit for most P4's but many won't get that far.....

You also don't mention your mobo, which *could* be the limiting factor. Have you run your memory faster out of sync to test its upper limit?

[GnomeWizardd]

a p4? naa get A64

[ryko]

keto---specs are in my sig....abit ai7

haven't tried asynch yet....but i think I am at my cpu limit @ 3.5ghz. When it's @ 255fsb, prime95 fails after a few minutes. My cpu is @ 1.6v, and extra juice doesn't help either.

Starting to think that my North Bridge is overheating. The original abit hsf died awhile ago, and i replaced the fan with a little thermaltake one. I just used the original blue hs, but took off acouple of fins so that the fan would fit flush on top. Might need to do something about that too....

[keto]

So, why not test your RAM to 275 async? Until you test it, you might buy cpu after cpu and not make the speed you want, only to eventually find out it's the RAM....

just a thought.

In any case, you wont find any useable difference in your computer's speed between 250 fsb and 275 fsb. 3.5 is danged fast, you get a 2.4C to 275 (1100) fsb it will only be running 3.3 and likely most apps *ever so slightly* slower than your 2.8C @ 3.5.

Could be the northy but I think you have it nailed when you say it's likely the cpu.

[muddocktor]

If you are getting 3.5 out of you present proc, then it would be pure dee luck if you get a 2.4C or 2.6C that will perform on par with that. My 2.6C is only good to about 3.2 and my 2.4 m0 2.4C is good to about 3.4-3.5 at it's max, but I run backed off from there a little. As much as I hate to say it, the 2.8E would probably be your best bet if your mobo can handle the extra strain of a presshot running overclocked. I wouldn't choose the 2.4E because of the lack of hyperthreading.

[ryko]

all of the reviews i have seen say the ai7 craps out with a presscot and major overclocking...

and for runnning asynch, i tried 5:4(cpu:ram), and i still can't get over 3.5ghz. So it's the cpu?

How can i get my ram running faster than the cpu? I only have the options of running 1:1,3:2,5:4(cpu:ram). I can't switch to 4:5 or anything. So my memory would be running slower than the cpu no matter what.......my memory is not holding me back it seems..........it's not even running close to its spec of 275fsb.

I just want to see if my memory is capable of running as fast as it is rated. My current cpu, and maybe motherboard are the limiting factors?

[entropy]

to hit 275, you're best bet is with a 2.4c ... but honestly you need to get a darn good one. A lot of the major hardware reviewers can barely eek out 275 with a 2.4c. If you *really* want 275, I would look into seeing if you can get your hands on an ES processor

[muddocktor]

Like entr0py said, your best bet then is to get a 2.4C, preferably in m0 stepping. I presently am running mine at 278 fsb and in winter I run it around 282 fsb. Your speed will be slower than your present 2.8C but your mem bandwidth should be a lot better. The only place I know of that guarrantees an m0 stepping is www.azzo.com and is where I got my 2.4 from. They are expensive however and I just looked and they don't have any in stock now.

Now if you want to work out a trade for mine, we might be able to work something out. I have pc4000 Corsair and I'm having to run 5:4 to run at this fsb speed and with a 2.8 I could run 1:1 and have a lot better memory bandwidth.

[madmat]

I was just looking on AZZO's site and saw a 2.4e 800fsb HT proc...that looks promising.
I'd kind of be interested in that if I had PC4200 or PC4400 for my rig. As it is I have PC3700 so I'd rather get a bigger proc but still...

[Jimborae]

I'm confused now, I thought 2.8e Prescott cores weren't as fast as 2.8c Northwood but some of the above recommend getting them. I'd be interested to know why as I'll be putting together another P4 system soon & as this one will be mine it will be overclocked & probably watercooled.

[muddocktor]

Jim, from what I've recently seen, some people have been getting some pretty decent overclocks out of presshot procs lately. However, if you want to overclock a presshot, be prepared for some serious strain on mobo components due to the extreme current draw required by presshot. Plan on installing sinks on mosfets and any other components on the mobo that will be under extreme load from running an overclocked Prescott. You will also probably need decent airflow throughout the case to insure that the sinks you install actually get rid of the heat.

I have read recently of 3.8-4.0 overclocks out of Prescott procs though, without using phase change.

[Jimborae]

Hi Mud,

Thanx for explaining that. 3.8 - 4.0Ghz eek!

Oh well, as this board will only be watercooled till I get my Amd 64 system up and running I've decided to go for a 2.4c P4. Also it will be running on RWB's old IS-7 board therefore it's probably good that I didn't go for a Presshott as it might not be able to take the strain. The stepping on the 2.4c is M0 SL6Z3, a quick google on this has revealed that it might be a good o/clocker. only time will tell, end of thread hi-jack:).

[muddocktor]

Jim, that is the same stepping 2.4C I have in my IC7-G and it folds 24/7 at over 3300 MHz. You better have some damn good memory though if you want to run at 1:1 ratio because it is definitely a high fsb runner. My PC4000 can't quite run at 1:1 becase my fsb is around 279 and it craps out around 270 or so.

[/end thread jack]