FPU:
- Rayshade, I let the machine calculate cblob.ray out of the Rayshade package
- POV-RAY, I let the machine calculate blob1b.pov out of the POV package
- Linpack, try to get it for MSDOS, so you can compare your CPU with Supercomputers
- I also use a couple of old Programs like Landmark 2.0 or Coretest 2.92 for a fast measurement of the System
Overclockers 1x1:
Overclocking is only successfull if your system work reliable and stable.
The deal is, you have to tune up the busspeed. In general, Intel CPUs are divided
into two categories, CPUs with busspeed multiplyers 1.5 or 2 (these are the models
P75-P133) and CPUs with busspeed multiplyers 1.5-2-2.5-3 (these are the expensive
P150-P200 models). The common busspeed settings are 50/60/66 mHz. Some
boards offer 55 mHz in addition to this, like the Gigabyte HX or the ASUS-T2P4
and most new Boards with TX chipset offer 75 mHz, this is especially for the
Intel/Cyrix CPUs which archieve performance out of overclocking the BUS.
A couple of Boards offer 83.33 mHz, like the ASUS T2P4 HX (undocumented),
or the A-OPEN (=ACER) TX.
The EIDE PIO MODE 4 speed specification is limited to 66,66/2 mHz busspeed. Also Intel
Pentium CPUs are limited to 66,66 mHz busspeed. But nobody can hold you back if
you want to do it. You don't burn your CPU if you try to overclock it, the
only thing that happens it that it won't boot or it will work for a couple
of seconds/minutes then it will crash or it will work with MSDOS 5.0 but
as soon as you boot Win95 it refuses to work. If you switch the computer off
and give your CPU the regular Speed, it will continue to work like it did
prior to overclocking.
In general most hardware take the busspeed of 75 mHz or 75/2 mHz, so this
mean if you possess the Intel P75 which is made for 50 mHz busspeed multiplyed
by 1.5, you can put it up to 75 mHz busspeed. This way you would get
a P75 working with 112,5 mHz. You can also try to make it work with
2*75 mHz, this way it would give 150 mHz, maybe it won't but it's worth
trying it. Every fourth P75 that I possessed so far did make 66,66*2.
The most important thing is that you need a heatsink with fan and some thermal
paste. I did doubt for long time that the use of thermal paste would be an advantage
but my own research proove that the paste is important for stable overclocking.
Some people say that it is possible to take super-glue instead of heat compound paste
but I'm not sure if this is good or not.
Also important is the heatsink and the voltage of the Fan. There are some
metallic-blue heatsinks that do not have a good heat-troughput-rate. I use
pretty small dark grey more plastic-like-looking heatsinks. The size of the Fan
is not that important, but in general a bigger fan means more air throughput than
a smaller one. Some people say that an odd count of blades is better than an
even count of blades but I don't have a proof for that. In general these fans run
with 12V, you can give them 5V to archive less working noise but 12V is the better
choice for stable overclocking.
Remember:
- Don't overclock your PCI Bus to 83.33/2 mHz if you possess a Diamond Monster Graphics Card!
- Make a backup of all important Data on your Harddisc prior to overclocking with 83.33 mHz
and check the Harddisc temperature. Just got to put your hands on it. You need an extra fan
if it is so hot that you can boil eggs on it
- Take it really serious! Check all cables and jumper settings before turning the PC on
- Make the first run just for a couple of seconds with MSDOS, then check the temperature of all
your components with your fingers
- Make the first run just with a Harddisc and the Graphicscard, no other Cards needed
- Don't expect P75-P133 CPUs to run with Clock multiplyer 2.5 or 3, that's something rare
- This is valid for Intel CPUs only, I have no experience with other brands
- Give your PC-cards and HDs enough room, overclocking means higher temperatures and they absorb the heat into the air within the case. The hot air is going out and vaporises fresh cold air in exchange
- A better heatsink/fan and the use of thermal paste will give you nothing if you don't overclock the CPU
One more thing before I tell you how to do it:
The P75-200 are 3.3V CPUs, there was the P60 with 5V prior to the P75.
I heard that it is possible to overclock this one to 66 mHz but I would not
recommend it because the P60 is already the hottest Intel Pentium CPU.
The PPro is really expensive and all PPro Boards that I checked out so
far did not go any further than 66.66 mHz CPU-busspeed, but you can overclock
them. I did run a PPro 200 with 233 mHz for long time stable and reliable,
I played daily 6 consecutive hours QUAKE with it for 2 weeks. They offer the possibility to
switch from 66,66 mHz *3 to 66,66 mHz *3.5, which is 233 mHz. They also can take
240 mHz with 60*4 but this do not work stable.
How to do it:
- Clean the top of the CPU and the bottom of the heatsink, with something that is dry
- Squeeze lots of small stripes of heat compount on top of the CPU and rub it firmly with a clean finger
- Clean your fingers and the edges of the CPU with toilet paper
- Put the CPU in the CPU-Socket and close the lever
- Snap the heatsink with fan on the CPU-Socket and attach it to the CPU real hard
- Check out if the heatsink is attached proper, it has to sit real tight on the CPU
- Power on your machine and see if it come up. The best is to start with just a MSDOS Bootdisk.
- If you successfully booted with the MSDOS Bootdisk, try to boot with Win95 and work a little bit with it. If it does´nt mock on you, the overclocking is successfull.
- If the computer won´t boot, switch off and set the jumpers back to a more moderate speed