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Overclocking a KT400

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Oct 30, 2002
New Jersey
This board has a divisor of 5 correct? The max safe speed for PCI cards is 33 mhz, and 166/5 = 33.3 mhz, so technically that would be the safest PCI speed.

However, does the KT400 have a divisor of 5 as well as the KT333, or a divisor of 6? I have NO PCI cards in my machine, everything is onboard, and then there's USB 2.0. Would I beable to overclock my FSB past 166? How is my hard drive affected by this?

warlo ckf: im gonna OC my comp
warlo ckf: so im gettin
warlo ckf: SLK-800 Heatsik w/ Sunon Ultra Quick 80 mm Fan @ 50 cfm, about 43 dbA, w/ arctic silver 3 thermalpaste, and 2 regular case fans - sunon 80 mm @ 36 cfm,

All of that + 3 day fed ex shipping is about 75 bucks. I was wondering if my temperature would drop from idle 44c to about 20c using all of that. I'd have 4 case fans, and the heatsink w/ the fan.

do you think I would need a shim to use with that heatsink? What does it do?
the only thing i can help you with is the shim. don't get it, i bought one that was supposedly 'made for xps' and i tried to use it and all it did was short circuit my cpu not letting it boot up and i turned it around all the possible ways still same thing then when i took it out it work.

Also I'm not sure the slk will lower the cpu that low but thats just my opinion, i never used one cause i use volcano 9 :p
The kt 400 does has a 1/5 divider for pci but does not have 1/6.
this allows you to safely run 166 mhz fsb without the chance to kill pci devices. although, pci is probably safe up to 38 if you have half *** decent devices.

I am running my fsb on a kt 400 chipset at 170 mhz right now and i am having no problems at all.
as for your temperatures, I dont know too much about the slk heat sinks never having had one.
if you are planning to overclock, there isnt much chance that you will get an idle temp of any lower than 39º idle on air. this is what i get with a volcano 9 on a oc xp1600 at 1800 mhz. and i have crazy ducting and air flow control setups. if you want to acheive temps like that, best to throw away that order and start building a water cooling system.

you never did mention which cpu it is you will be overclocking.
It's in my signature, I have an athlon 2200 XP. Dude I was able to OC from 13.5x133 to 11x170, looped 3DMArk a few times and it worked fine. My dad went to use the computer and the screen just went black. SO I turned it back to default. I noticed that when I flashed the bios from 1005 to 1008 it read 44c instead of 50c, so i'm assuming that's the correct reading.

I got down to 37c idle w/ my STOCK HEATSINK when I turned my multiplyer down to 9. How is the hard drive affected by the increasing of FSB? Is it the same, 33 mhz or what? Besides, I have all onboard stuff, does the same 33 mhz apply to them as well? It's all new on the Kt400 which is a rather new and great motherboard.

My PCPitStop MArks beat out those of a much faster Pentium Processor w/ much better video card, astonishingly!

I've looked at some recent reviews. The delta 80 mm fan ran w/ the SLK-800 Heat sink showed 24-27 Idle, 30 avg, 31-32 Full load. That is excellant temperatures, however I am getting a 50 CFM Sunon 80 mm fan w/ my heatsink, arctic silver iii... so i assume that i'll beable to get just the same, if not 22c idle.

If that's possible, how high do you think I could OC my machine? 13.5x166? 9x200? 10x200?

Also, I have all onboard stuff, it's pretty much new... does the same 33 mhz rule apply to them? How about my HD?
The only reason KT333 barely beats KT400 in benchmarks, is because of the 8x AGP and the drivers. They are suppose to fixing this problem in the latest VIA 4 in 1 drivers. Then the KT333 will stand no chance to the KT400 in benchmarks, even though it doesn't now anyways o_O
I wouldn't expect temps that low. I have an AX-7 and a Sunon 50cfm 80mm fan on it. My idle temps are 35-37 and load is 39-41. Depends on the temperature in my room. The SLK-800 is good, but it won't do what you're expecting, especially if you will be going for a big overclock.
And as far as overlocking that chip goes you will likely see 1.9-2ghz out of it. The TbredA's don't seem to be able to get pasted that.
Good luck! :)
yea, these heatsinks are mainly designed for high speed fans like the Delta's and Tornado's which have the craziest airflow (and noise levels) for 80mm fans, I would never expect to see idle temps of 22c out of 50cfm fan, SLK-800 is still the best heatsink around tho, and a 50cfm fan still has a good noise/performance ratio. It depends on your ambient temperature and the airflow you got in the case, I also made "Ducts", I cut a round hole on the side panel, right above the CPU and put a fan and a funnel there, directing the cooler room air onto the CPU fan, it lowered about 4-5C of my CPU temps, if you're gonna be running high speed fans on the heatsink even like the 50cfm SUNON, get at least a 92 or 120mm fan for the duct, if you're gonna do it, if not, then making good air flow in the case is very important, you should have intake in the front bottom and outtake at top rear or top of the case. that will help temps a lot also. But unless your room temp will be 10C don't expect 22C on your CPU.
These T-Breds, run Ultra hot anyways, so I wouldn't expect a really low temp out of them anyway. and yea, I think that the most people were getting is about 2100MHz on good watercooling, so I would expect about 2000-2050MHz out of that CPU.
The PCI speeds won't affect the HD much unless they're some crazy speeds like over 45MHz. But it depends on the HD, and its quality, Maxtors and Seagates are known to work well while on high PCI while others don't, but that doesn't mean that the HD will not work. High PCI speed will cause data corruption and might even require reinstall of the OS, I once had my FSB at 167mhz, can't remember, what HD I had then, either my new Maxtor or an old Quantum, but I didn't have any corruption (my mobo doesn't have the 1/5 divider).
WTF do you mean T-Bred's can't get past 2100 Mhz? My cpu runs at a lower temperature when the multiplyer is decreased. Right now it's at 42c, 10x180 FSB. Don't tell me it won't beable to reach 2.2 or 2.3 off air cooling, especially w/ an SLK-800.

The SLK-800 & Delta 80 Mm fan combo pulled off 24c idle on an athlon 2200 i believe.

Retail steppings on processors are better than steppings on non-retail processors... so I highly doubt the other T-Bred users who used good water cooling had good stepping at all.

I have an awesome machine w/o a half decent video card, and good cooling as it is w/ just a stock HSF. I believe w/ a Sunon 80 mm & SLK-800 & Arctic Silver III, I can pull off an idle of 25c or lower.

Who thinks I could OC from 1.8 to 2.2-2.3?

The KT400 won't run 9x200, even though it should I have no idea why.

Can someone help me get the Kt400 (non-ultra) to run at 200 FSB? Tell me what my settings should be at. I have NO PCI cards in, just USB/Serial/AGP/HD.
The T-Bred A (which is what you have) will not reach 2.2-2.3, it might reach it using water cooling or some kind of super cooling, it doesn't matter what temps you got (also when lowering multi, ur lowering the speed, so its pretty much obvious for the temps to drop), its the limitation of the chip not to be able to reach high speeds, that's why AMD revised the chip and now there are XP2400 and higher which we call Tbred Bs.
You might be lucky and get to high speeds, but from most people I didn't see anyone who's doing more than 2100 on air. Sorry