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8k5a2 and xp1600+ overclock

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Oct 25, 2002
trying to figure out how to do my first overclock of a cpu. i've got everything running with no problems currently, but want to overclock this 1600+ to 166fsb if possible.

my specs:
xp 1600+ (0204 K stepping... that gonna be a prob?)
thermalright sk-7 with as3
512mb samsung 2700

there was a jck1 jumper defaulting to 100mhz cpu clock, but i moved it to 133.

when i got into the bios, all i changed was cpu clock to 166. hit f10 and rebooted. didnt change anything. still booted up as 1400mhz. when i went back in to bios, it had it at 133 again. this time i changed the vcore to 1.8 and the cpu clock to 166. same thing again. however, the vcore is *still* 1.8, so i know its not resetting everything.

what am i doing wrong in the bios? any settings i'm missing or not changing and should be?

I have the same rig(run different processors, but that shouldn't matter), so let's see:

1. Enter Bios the usual way(DEL)
2. Enter Frequency/Voltage Control
3. Enter CPU CLock, probably says [133]
4. A window will open and it has:
min 133
max 255
key in a DEC number :
5. Enter 166
6. Your new CPU Clock should say [166], and the AGP/PCI should be at defaults(66,33) because of the dividers at 166
7. MAKE SURE Watch-Dog Timer is disabled, it will force the boot with the new specs and not dump if they are to high. If you do lock-up you can always just reset the BIOS by turning off the power(completely the toogle on the PS or unplug) and moving the DIP switch on the motherboard JBAT from 1-2 Normal to 2-3 Clear CMOS, leave it there for about a minute, then put it back and power up and you should be back to default settings...

Try that and let me know how it works...
well, it appears i was doing everything right all along. i tried 150fsb and everything came up roses. i guess the chip is limited. maybe i'll take gameve up on their offer and grab their Z stepping as exchange.

i just wish i could hit 166 so the divider would kick in. at 150, i'm looking at 75/37. what is too high?

Unfortunatelty there is no "too high", it all depends on your gear. Most people will set certain "safe" limits on PCI and AGP frequencies and also on VCORE and VDIMM, but like everything else it's mostly trial and error.

What is the rest of your rig like? I know your MB and CPU, what about your cooling, hardrives, video, etc...
Its a concern those high pci/agp speeds but remember that many who can tell sad stories probably was using kt266 pushing pc2100 modules. Same as if you went for 200fsb, more or less. You are better off. Biggest enemy is hd - some just dont like any higher than XX ;) Im in same position, at 155 but can do 160 easy. Not sure what will be permanent setting. At such situations someone mentioned a trick: lower UDMA mode for hard disk - make a 100 model 66 and so on. You wont lose much speed, outside benches probably zero, and hd is more likely to handle the higher speeds.

I did some heavy searching for my specific hd - very good at high pci mhz it seems. A bit more worried about an old Maxtor but only keep games and such on that one. Dont trust it too much yet.

Have tried getting corrupted hd before, cant be recommended. Was at 152-154, kt133a, apacer mem for months but then I had to try faster timings - not a good idea. Went wrong very quickly :) Lesson learned... Now I use half-bad Samsung pc2700 DTM/DTL memory with wpcredit tweaks and max timings they can do 2-3-6-3-1, not worried about that. If I try 2-2-5-2-1 I give computer 1 hour to live. 2nd Samsung stick on this mobo - been there ;) If you have DTL or DTM please keep 3-6-3, only test under "safe" conditons like different OS, best dif. computer...
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--using a thermalright sk7 with a smartfan for cpu. couple of vantec case fans and couple of plain antecs that came with the plus860.

--video is gainward ti4200 128mb golden, oc'ed to 296/556 at the moment. very stable with no artifacts and a 10228 3dmark at default settings when my cpu is at 1586mhz.

-- WD 80gb w/ 8mb cache running winxp (and right now i also have an old hd on the 2nd channel bringing files over before i slap it in son's computer)

--only 2 pci's are a NIC and a firewire 3-port.

--512mb of samsung 2700 one stick (should i try messing with the fast/fastest/turbo with this ram??)

i just really dont wanna screw up my video card by having the agp too high. comp kept crashing and rebooting at 156fsb. maybe if i tried more voltage...?

you have plenty of good cooling, your memory should be fine, your video card should be able to handle it, I know the WD drive should have no problem, not sure about the other one, the only weak spot might be your NIC card, they are notorious for being the weakest link, if you want to run a test, pull it, set Watch-Dog Timer to enabled, set the CPU Clock to 166 and reboot, see if that gets you the 166FSB and dividers you want, you could try up'ing the voltage VCORE/VDIMM, but don't go past 1.85 VCORE and 2.8 VDIMM, and keep and eye on your temps after you do up them. If it posts and Windows loads trying running Prime95 overnight...
Dont think you have to worry about vcard. If agp port cant handle it you might get infinite loops, bsods, lockups etc. but blowing vcard? Anything can happen I guess but doubt that will be it. Could kill some oc limits though.

As said check which kind of Samsung you have. At least DTL/DTM have 2-3-6-3 as SPD under 166. I suggest you leave them alone, rest I have max/best/lowest - no problems. I use +0.1v, default works ok too. But timings can be deadly on newer Samsung. If old CTL you are very lucky :) CPU command decode thing is enabled under 166 (on 2+ it is) so with high fsb it wont be a slow computer.

Nics even worse than hds regarding pci sensitivity Ive heard :) well trial and error will tell you - at least you wont corrupt data testing those.

WDs very popular, should be easy to find out how well they deal with close to 40mhz.

btw. I have trouble using any of the presets in 2+ bios. I did manage to take a wpcredit picture at turbo so can compare with what I get at "normal" + my own tweaks. Think I know which register setting it is (AD:98 on "turbo", "normal" AD:08) but not too bothered.

btw2. Try put your finger on NB heatsink at 160fsb! many many concerns - on a hot summerday, heavy gaming etc etc. nah Ill keep the 155, at least for a week more ;) I did use thermal paste instaed of stock pad but not exactly cold that one...
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