I've got a k6-2 400 mhz, and I want to overclock it to lets say, 450 mhz. But I want to get a higher bus speed than 100 Mhz, since my motherboard (FIC 503+) supports up to 124 mhz FSB, and my ram is Kingston PC133 ram (128+64, both same model/brand).
Now this is what I wonder, the K6-2 itself has 100 mhz bus speed.. so if I overclock the bus speed to about 115 FSB mhz, with 450 mhz clock frequency on the cpu, wouldnt the cpu die? I mean, the motherboard supports 124 mhz fsb but not the cpu.
Running the K6/x series on higher FSB speeds will not hurt them. I had a K6/3-350 running on a Gigabyte GA-5AX at 115mhz FSB*4x multiplier for 460mhz for a long time. I needed 2.7v to be stable, but it didn't hurt the chip. Even thought the K6/x series was originally made to run 100mhz FSB, they are really responsive to running higher FSB speeds. That is where your performance boost shows up. You memory bandwidth increases a lot which help performance the most.
Your biggest problem though is your PCI bus running out of spec. I think at 115 FSB, the PCI is running 1/3 divider and is 38.3mhz. That may cause problems because a lot of cards do not like that high of PCI setting. Your sound card, video card, or modem may cause you problems. Older Maxtor HDD's do not like this high of a setting either.
Try it and see. Your FIC VA503+ only offers 112mhz and 124mhz settings doesn't it? My friend has one running a K6/2-500 at 560 using the 112 setting w/5x multiplier. His is an older version, but I thought they were limited to those settings. He also has not had any trouble with his and it's been running for several months now. He is also using PC100 SDram without any trouble.
You should be fine... Good luck!
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Thanks AMDnut. Also I'll probably get a k6-3 450 mhz for the same motherboard in a month or so, and I wonder if I can overclock it to about 600 mhz, even tho the motherboard supports max 550 mhz cpu? And I guess the k6-3 is a much better performer in games because its got better FPU.
I assume you are talking about the K6-III+, the K6-III (original) will never get to 600MHz.
Oh, and I have a K6-2 400 running at 473MHz (105x4.5) at the moment at 2.4V (the default voltage for my K6-2 is 2.2V). It hasn't given me any problems. I would probably have gone for a higher FSB, but I worry about the hard disks and the graphics card etc. getting damage. I don't worry about heat as I have a GlobalWin FOP32-1 on the K6-2 and it barely gets warm at those overclocked speeds.
Speed is everything - Warp factor 9, Mr. Sulu!
USSVoyager is correct, the original K6/3 "Classic" will never reach 600mhz. I've never seen one break the 500mhz barrier. The cores just won't do it. The L2 cache keeps the K6/3 Classic from going much higher. But the new K6/3+ chips are hitting 600mhz pretty easy nowadays. I've seen the 450's hitting 550 without any trouble and most hitting 600mhz with good cooling and a nice voltage bump.
As for the K6/3 having a better FPU than the K6/2, I'm not sure about that. I was under the impression that both had the same core/FPU and that the only difference was the addition of 256kb of L2 cache. I'm pretty sure that the only difference between the "2" and classic "3" is that the "3" has the L2 cache running on-die at full processor speed. This allows the motherboard cache to run as L3 at FSB speed. The K6/2 had no on-board L2 cache.......
If you are going to look for a K6/3, the only way to go is with the "+" series chips. They will work in your FIC VA503+ from what I've read, but you will need a BIOS flash I believe. You can support 600+mhz by using the 2x multiplier. The 2x remaps to 6x so on your FIC, you would have the following options above 550 assuming you are using a new K6/3+ series that will reach the higher speeds:
Most of these are not really obtainable. The 124mhz FSB is really difficult to run stable, if you can even boot with it. Some people have done it using PC133 memory and been very lucky, but most boards will not tolerate it. The ALi chipsets on the Gigabyte boards are the best for higher FSB speeds, the VIA MVP chipsets really hate anything above 112mhz. Even if the board will reach 124, the peripherals won't like the PCI speed of 41mhz. At 41mhz, damage can happen to a lot of hardware. And I don't know of any boards other than Gigabyte that offer 1/4 dividers for the PCI bus. Even Gigabytes doesn't kick in until 125mhz FSB, which makes it useless anyway!
You might want to check out the AMDzone forums, there are 2 or 3 people there that have the K6/3+ chips running at or close to 672mhz. Those are the best I've seen.
Hope this helps!
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WOW, I haven't been over here on the light side for a long time! ** reaches for his shades ** I've got k63+ on the fic va503+. It runs real good! currently 5x112 for a "bios" reported 556Mhz. You will have to flash with the je4330 bios forun on the tiawanese FIC site. The newest for the 503+ is je4333, it adds support for LARGE harddrives! 80G+ and also solves the winME misreporting of the SM bus under the system heading in the device manager!
I run Genome@Home on my k63+/VA503+ with TurboLinux 6.2 and the 2.4.3 kernel. It is quick AND stable!
Email me if you can't find the bios flash. That website is a MESS and hard to navigate through!
Plans for my k63+ include removal of the "hood" and addition of a copper shim with a pelt and water! Everything to be held together by ArcticSilver Epoxy I want 600+ from her, aka 616. Oh yeah, she is a 450 stocker!