Dual P3 OC'ing...any experiences?

[PixelMover]

Silly question (I hope not...)
Are there any need-to -knows regarding oc'ing dual cpu's? or just simply make sure you use the same settings for both cpu's?

running 2 P3 1gig on an Asus CUV4X-D

[Endeavor]

you dont need to keep them at the same speed when overclocking a duallie but if you it throws the software out of whack and it makes it act all weird and it can assign the tougher packets to the slower CPU
so its best to have the speed as close to equal as possible if not equal

[Kingslayer]

I have a teeny tiny amount of experience with overclocking and dualies. I will start by saying that there isn't any real difference with dualies and singles. You have to pay more attention to your heat because you have two CPUs. You also need to pay attention to your chipset, they will run hotter with two CPU's.

And there isn't a board out there that will run the way Endeavor described.

If you get duals, get the same speed. The same stepping. And if you can hand pick your chips, get them from the same lot and as close as you can number wise. You don't have to stick by this last one, but the closer the chips are, the more even your attainable speeds will be.

[outhouse]

Remember that duel CPU's do not overclock as well as a single chip most guys are getting there 1g p3's to about 1100 if that, other then that overclocking them is pretty much the same.

[burn'em]

i have Dual PII 450 on an Asus P2BD I only have one setting to oc both cpus. I can only get 504mhz out of them. I a mob problem.

[PixelMover]

If overclocking will only gain me around 100mhz max...I guess it might not be worth the risk.. Stability will probably be a better bet for me than overclocking, with this setup being used a lot of hours in the day..
And yes, I'm running W2K. It's the only os to support duals anyway, right?

[vimal]

NT4, Win2K and some flavor of XP all support dual processors.

If this is a mission-critical server for a company or something, then you shouldn't overclock, not even for the extra 100MHz. On the other hand, if this is just a server for you, maybe a low traffic web page or files or something, then overclock away. If you can run programs like 3DMark2000/2001, Prime95, SETI and/or Folding at home, high-res winamp visualizations (or some combination thereof) and other CPU/memory/graphics intensive apps continuously looped for 24 to 48 hours without any crashing or errors, then it is pretty safe to say your system is stable enough for all practical purposes.

The big thing to watch is heat, especially with newer PIII's. Make sure the heatsink is properly attached to the core and get plenty of case airflow.

My dual 550's run at 617, and I can feel the speed increase in regular apps. (I think they could do more, but my mobo has 100, 112, and 133 MHz FSB speeds, and 133 is right out of the question) 100MHz on 1GHz may not be as noticible, but every MHz counts.

[Kingslayer]

You should gain more than 100Mhz. Now, the PIII's top out about 1200 anyways. But the thing to remember that Mhz isn't always the gain. You have to remember that you will increase your FSB which will increase bandwidth throught the system as a whole. That is a good increase in speed there.

[phoenix]

i have 2 dual p3 700e's on vp6's one runs at 980, the other at 910
both have a vcore of 1.9 and run quadrant pc133 cas2 (wont run 133 at cas2) probably whats holding me back

[Kingslayer]

What are your temps?

[SP]

When overclocking on a dual motherboard you do so using the FSB. Since there is only one FSB, this setting is the same for both CPUs. So, if the multiplier setting is the same for both chips your gonna have to run them at the same speed. Now, I have heard of people running 2 different CPUs with different multipliers and therefore at different speeds on some dual motherboards and it worked, but this isn't recommended even though on some boards it may be possible. Anyway, you have to run both CPUs at the same FSB because there is only one FSB and therefore only one setting for it.

Another thing to keep in mind is that with SMP the timing requirements are more strict. That means that if you have 2 chips that will run at a certain speed individually they may not necessarily run together at that speed in an SMP configuration. That's not to say you can't overclock an SMP system. You can and there are many who have great success in doing so. It's just that sometimes it can be a bit more challenging.

[CrystalMethod]

Just reference infomation here...
I put together two dual rigs today :Asus cuv4x-d, w/ 1Ghz Intels, 512M oem (infineon chip) RAM. As a rule, I install and bench all dual CPU systems I build, even if they're not being shipped with an OS. Company policy right now is "build it, check for hardware conflicts, and ship it out". Usually isn't a problem with single CPU systems, but with duals, I'm more cautious. Anyways, I started by installing win2k & service pack 2. Installed Direct X 8.1, Installed and ran 3D Mark 2001. Locked up HARD on the last test ( "point sprites"), if I remember correctly. I also ran "Heavy-Load" for 4 hours before it ran out of memory (annoying beeping stuff after that). I'll try and run some more stuff to see how it does, and maybe try Oc'ing it a bit before I ship it (Shhhhhhhhhh!!!!!). But as far as your original question goes, all of the boards I've worked with (Aopen, MSI, Asus, and Intel), all require you to have the same CPU speed. The Intel's being the most finicky of the bunch. Not only do they need the same CPU's, but most memory is incompatible with the MB. Jon is the one you really need to get in touch with regarding dual setups though. Haven't heard too many great things about OC'ing duals though.