P4 2.4c or P4 2.8c on P4P800 Deluxe

[benjamat]

Hi Guys,

Message title says most of it.

I have a new P4P800 mobo and some sticks of Crucial 2700 which I hope to run at 800

Obviously overclocking CPU but which would be the best, I would like to get to 3.2.

Secondary question,

If running Cpu (2.4) at 3.2 would I be able to keep ram frequency down to 400

I had better say after viewing earlier posts, I mean - (166@200) (x2 - ddr ) (x2 - Dual channel )

Would 2.4 clocked to 3.2 on an 800 mobo mean 1200!

many Thanks.

 

[benjamat]

Anybody Please or point me to a thread.

Thanks

 

[Soulkeeper]

get a 2.4 if you want to oc mem/fsb real high and also save money
got 2.6 or 2.8 if you are more worried about cpu clock speed
although the difference is prob minimal in the long run

i suggest a 2.4 or 2.6 800fsb


good luck


edit: ok i noticed you said some pc2700 maybe the 2.8 wouldn't be such a bad idea if you want to have everything maxed out 1:1

 

[RalfHutter]

Either CPU would probably do 3.2, it's your RAM that I'd be real worried about. I highly doubt that Crucial PC2700 would be able to do PC3200, at any timings.

Just for the sake of argument, lets say that it does. In your second question you ask if you could keep the RAM at 400MHz if you run a 2.4C at 3.2GHz. The short answer is "no".

You only have 3 dividers to choose from on this board: 1:1, 5:4 and 3:2. 3.2GHz with the 5:4 divider would give you RAM speed of 213MHz or DDR426 which that Crucial would never, ever do. 3.2Ghz with the 3:2 divider would give you memory speed of 177MHz or DDR355 which the RAM would probably do, but no guarantees.

If you want to OC a 2.4C CPU and keep your RAM speed at 400MHz while using a divider the best be would be to run the CPU at 3.0GHz (250MHz) and use the 5:4 divider which would give you memory speed of 400MHz.

Now lets look as the various permutations of the 2.8C CPU and memory dividers. Running the 2.8C at 3.2GHz with the 5:4 divider would give you memory speed of 182MHz or DDR365 which that Crucial might do. Running at 3.2 with the 3:2 divider would give you RAM speed of 152MHz or DDR304 which the RAM would surely do.

If you want to OC a 2.8C and keep your RAM at DDR400 you'd need to run the CPU at 3.5GHz which is possible but not guaranteed. If you ran that with the 5:4 divider your RAM would be running at DDR400.

 

[benjamat]

Excellent reply.

Thanks very much

 

[jhites]

First - if you have not bought your chip yet. I would wait until after the 26th intel scheduled price drop. The 2.6C will be at the same price as a 2.4C is currently. You should also consider a 2.6C with that setup. With that ram you will find that the total system will be faster with a higher fsb on the cpu even if the memory is running lower DDR speed.

Example: 2.6C @ 246fsb (984Mhz bus) = 3.2Ghz most likely with default vcore
------------ Mem @ 5:4 DDR394 (maybe with 2.85vdimm that's available)
------------ Mem @ 3:2 DDR328 ( obviously not a problem even at default vdimm and tighter timings)

 

[benjamat]

Thought this might be usefull for P4P800 owners

P4C FSB & Memory Permutations.

P4C 2.4 Ghz

P4C X Divider FSB Set GHZ Out Memory DDR
2400 12---1 1 200 2.40 200 400
12---5 4 200 2.40 160 320
12---3 2 200 2.40 133 267

2400 12 5 4 210 2.52 168 336
5.4 12 5 4 220 2.64 176 352
12 5 4 230 2.76 184 368
12 5 4 240 2.88 192 384
12 5 4 250 3.00 200 400
12 5 4 260 3.12 208 416
12 5 4 270 3.24 216 432
3.2 12 3 2 210 2.52 140 280
12 3 2 220 2.64 147 293
12 3 2 230 2.76 153 307
12 3 2 240 2.88 160 320
12 3 2 250 3.00 167 333
12 3 2 260 3.12 173 347
12 3 2 270 3.24 180 360

P4C 2.6 Ghz
P4C X Divider FSB Set GHZ Out Memory DDR
2600 13 5 4 210 2.73 168 336
5.4 13 5 4 220 2.86 176 352
13 5 4 230 2.99 184 368
13 5 4 240 3.12 192 384
13 5 4 250 3.25 200 400
13 5 4 260 3.38 208 416
13 5 4 270 3.51 216 432
3.2 13 3 2 210 2.73 140 280
13 3 2 220 2.86 147 293
13 3 2 230 2.99 153 307
13 3 2 240 3.12 160 320
13 3 2 250 3.25 167 333
13 3 2 260 3.38 173 347
13 3 2 270 3.51 180 360

P4C 2.8 Ghz
P4C X Divider FSB Set GHZ Out Memory DDR
2800 14 1 1 200 2.80 200 400
2800 14 5 4 200 2.80 160 320
2800 14 3 2 200 2.80 133 267

2800 14 5 4 210 2.94 168 336
5.4 14 5 4 220 3.08 176 352
14 5 4 230 3.22 184 368
14 5 4 240 3.36 192 384
14 5 4 250 3.50 200 400
14 5 4 260 3.64 208 416
14 5 4 270 3.78 216 432
3.2 14 3 2 210 2.94 140 280
14 3 2 220 3.08 147 293
14 3 2 230 3.22 153 307
14 3 2 240 3.36 160 320
14 3 2 250 3.50 167 333
14 3 2 260 3.64 173 347
14 3 2 270 3.78 180 360

Example - 2.4c O/C to 250mhz runs at standard PC2700 memory speed with 3.2 divider = 3.0ghz

However a 2.8c at 250mhz whilst running stock 166 (333) for PC2700 would need to achieve 3.5ghz (Very High)
To run a 2.4c at 3.2ghz the fsb needs to be 267mhz with 3.2 divider giving 355mhz memory settings (Possible with good PC2700)

Hope this is usefull
:gift:

 

[benjamat]

God I hate the way these pages destroy formats

 

[1966]

Originally posted by: benjamat
God I hate the way these pages destroy formats

take a picture of it then post it here. --- > http://pics.bbzzdd.com/

 

[1966]