"sticksen" said:
Hi there,
i want to overclock my P4 2.8 GHZ. Only at a fsb 250 MHZ my system boots up
at a speed for 3.5 GHZ. Well done. In smaller steps the system dosn't boot.
But when i am rendering some videos in DVD, it hangs up after 10 minutes.
Even some benchmarks programms failed after minutes work.
The settings in bios are all "AUTO". Which settings must i use for a stable
system??? I don' t know....
Please help!!
System: ASUS P4P800 Deluxe, P4 2,8 GHZ, Corsair 2x256 MB CMX PC 3200LL, 430
W Enermax, Radeon 9500 Pro, 2x Maxtor 80 GB SATA Raid 0.
thanks sticksen
The applied voltage to the parts, has to be adjusted for
the conditions. The Vcore on the processor can be increased
a bit, to aid stability. But, to do this responsibly, you
look up the datasheet for the processor on developer.intel.com
and determine the absolute max core voltage. Here are some
examples of Vcore values not to set in the BIOS. You want less
than these values. While increasing the voltage can improve
stability, it also makes the processor run hotter, and a Prescott
will start to thermal throttle if it goes near 70C. Throttling
will give lower benchmarks, and an overclock without adequate
cooling is pointless.
Northwood Pg.23 1.75V absolute max
ftp://download.intel.com/design/Pentium4/datashts/29864312.pdf
Prescott Pg.21 1.55V absolute max
ftp://download.intel.com/design/Pentium4/datashts/30056102.pdf
Similarly, high performance memory needs a bit of voltage as well.
Check the datasheet for the Corsair memory on corsairmicro.com
for the max they recommend. I think I see 2.75V for that. (Note -
memory is funny, in that some parts don't seem to benefit from
more voltage at some point, while others just get sweeter, the
higher they get (Winbond BH-5). In some of the private forums,
I've read threads where people damage their motherboard or burn
out the memory in a single overnight test run, by using too much
voltage. My Ballistix memory, for example, is not tolerant of
too much voltage. I would try 2.75V or 2.8V with your memory,
but would not bother with devices like DIMM boosters.)
There are several CPU:memory clock divider ratios available on
875/865 boards. Setting your memory to "DDR333", while overclocking
the motherboard to FSB250, results in the memory running at
250/200 * DDR320 = DDR400, which is the rated speed. The DDR333
memory setting is referred to as the "5:4" divider. The DDR333
setting is actually DDR320 in the Intel chipset (as noted in your
user manual). When you use the Asus automatic overclocking BIOS
settings, sometimes they use an even lower setting, which runs
the memory slower still - that is a reason not to use the
Asus "percent" settings, as they do a poor job of choosing settings.
The P4P800 board can get video artifacts, if you use FSB250
and set the memory to DDR400 (DDR400 is the "1:1" divider).
In your case, 250/200 * DDR400 equals DDR500, and that is close
to the limit for your 3200XL. Your 3200XL has a higher top end
than my Ballistix PC3200, but you may find that your video card
doesn't work well under those conditions. I've seen claims that
certain brands of memory work better in this regard, but only
your testing will tell you whether you have that problem or not.
The 865 Northbridge is speed graded, and is a slower part than
the 875 (on a P4C800 type board), as Intel selects the good ones
to make 875's, and the 865 is the next speed bin down. So, if you
see the video artifact problem, try selecting DDR333 in the BIOS,
which results in an actual speed of 250/200 * DDR320 = DDR400.
I presume the BIOS is reading the SPD chip on the DIMM and
getting the right timing values for the DIMM in both these
cases. At an actual running rate of DDR400, the DIMM should
run at 2-2-2-5. At a rate of DDR500, it will be more like
2.5-3-3-7 or 2.5-3-3-8 or the like.
As for the actual BIOS settings themselves, as "lakesnow" points
out, trying the different values and learning how to use the
BIOS yourself, is the best teacher. I would avoid any BIOS
setting that uses the words "turbo" or "streetracer", as nobody
knows exactly what they do (without testing of course). Turbo,
for example, causes many people's computer to fail to post,
and the reason is, Turbo blindly selects 2-2-2 timings, and
unless you have a memory that supports those low latency
settings, the computer will freeze at POST.
Selecting a "standard" setting, and then setting values
manually, is a better course of action (like those memory
timings mentioned above), as then you know exactly what you
are trying to do.
You can also learn a lot, by doing searches here. There is
usually a huge thread about some of the more popular boards,
and you can now search within a thread (there is a search
box at the bottom of the longer threads).
http://abxzone.com/forums/search.php
This is one thread I point P4P800 people to look at.
It is the "video artifact" thread:
http://abxzone.com/forums/showthread.php?t=62275&highlight=p4p800
Here is a thread, with examples of what people have used
for settings.
http://abxzone.com/forums/showthread.php?t=51084
Also, a word of warning about overclocking. The hard disk can
be corrupted, if settings are selected that cause the disk
interface to run at an out of spec speed. For PCI bus based
hardware, AGP=75MHZ plus PCI=37.5MHz are considered the limit
for safe operating values. More than PCI 37.5MHz on an IDE
interface can result in corrupted hard drive data. SATA drives
also have some issues, but I'll let you research those
yourself, as SATA conditions vary with motherboard/chipset.
My experience is, there are a couple of "safe" ways to test.
I use a floppy drive, and a copy of memtest86 (memtest.org),
and boot the computer with the memory tester, as a first
test. You could leave the hard drive totally disconnected
while doing testing that way.
Another thing I found handy, was to get a copy of the
Knoppix (read-only) Linux disk. It is a 700MB download,
which is not something you want to try with a dialup modem.
Using Knoppix, I disconnect the hard drive, and boot with
only the CD drive connected. You can tell from the error
messages on the screen during boot, whether you are unstable
or not. Programs will start disappearing from the screen
while you are working, if the motherboard is not stable. I
find Knoppix an amusing and useful environment for testing.
And, running a Linux version of Prime95 (mersenne.org), allows
a stress test, once you've managed to boot the Knoppix CD.
Once Prime95 will run for hours without error, then it is
likely safe to connect the hard drive back up, and boot into
Windows.
In any case, have a backup of your Windows disk, at least
for as long as it takes to prove the computer is indeed
stable. There is nothing worse than corrupting a disk
while playing around, and not having a backup.
HTH,
Paul
