"Turbo1010" said:
What is the fastest CPU a P4C800 Deluxe board can take. I currently have a
2.6 processor, and would like to max out the board. I am not able to
Overclock the board, without it erasing the bios. Everytime I try to
overclock, it says bad bios, and wants the cd to reflash it, even though I'm
running the latest bios. I have Corsair PC3500 ram in the board, 2 stick,
512 meg ram each. Would a faster processor give me a performance boost?
http://www.cpudatabase.com/CPUdb
If you look at the data on FSB800 processors in the "cpudatabase",
it should be apparent to you that the typical overclock for all the
FSB800 processors is in the neighbourhood of 3.6GHz. So, even if you
buy a 3.2GHz or a 3.2GHz EE, they still aren't going to go
appreciably faster without a Prometeia beer fridge.
So, lets do the math and see what potential you've got. The CPU:Memory
ratios are 5:4 and 1:1. Since you don't have PC4000 memory, then the
5:4 ratio is the one to use. Your PC3500 gives you DDR440 to work with.
The 5:4 ratio will display "DDR333" on the screen, but is actually
DDR320 in fact (as stated in the manual). Given these numbers, your
best overclock is:
DDR440
2.6GHz * ------ = 3.6GHz (how far you can go with 2.6GHz and DDR440)
DDR320
In other words, you already have the materials to go fast.
In terms of priorities, the first priority is to get a fast core clock.
Even if your memory subsystem sucks, a high core clock can still do
useful work when "compute bound".
The second step is to optimize memory bandwidth. For every 10% memory
bandwidth improvement, you might squeeze another 3% equivalent CPU out
of it. In the case of the 875/865 boards, the way to do this is to run
the CPU:memory at 1:1. The cheapest way of getting there, is to assume
the final target is 3.6GHz, and the use of PC4000.
DDR400
3.6GHz * ------ = 2.88GHz (what you would need at 1:1 assuming DDR500)
DDR500
So, a 2.8GHz processor and a couple of sticks of PC4000 memory (for dual
channel) would give you the ability to overclock close to 3.6GHz and
run the memory at its rated speed of DDR500.
Now, as far as your current configuration, start by backing off on the
memory timing. Don't try to run at 2-2-2-6 or something, because it
isn't going to happen. Try 3-4-4-8 to start, until you get things under
control. Turn off "turbo" and any other goofy optimizations and
take control for yourself. Maybe by doing that, it will get past the
BIOS.
And look in the abxzone.com site for more inspiration, because there
are plenty of posts over there on overclocking 875/865 boards.
Increasing the voltage on the DIMMs a little (2.6 or 2.7V) will
help a little. High performance memory uses chips that are actually
spec'ed to run at 2.6V nominal. Lower speed DDR is spec'ed to run at
2.5V nominal. So, running at 2.6 is not overvolting. (Check the
manufacturer info for your DIMM, to see what they suggest is the
absolute maximum voltage for the DIMM. Generally this is 2.85V or
so, but verify using the DIMM manufacturers info.)
If you are going to overvolt the processor, stay away from the absolute
max. I think it is 1.75V, so maybe 1.65V is where you should stop. If
the processor will make it to 3.6GHz without overvolting, so much the
better.
Have fun,
Paul
