overclocking AMD 850

[welshexport]

:( I would like to oc my AMD 850 which is set on a QDI Kinetiz 7 with VIA apollo KT-1333A chipset I'm new to OC,,,and have read the forum but not many of you are running older cpu's,,,I've over clocked my old celeron 466 and its still running but the bios seem more user friendly,,,,,I've got a new artic cooling fan for the AMD 850,,,,can anybdy give me some advice apart from buying a bigger CPU
Thanks Welshexport

[juliendogg]

not much i'm afraid. I'm guessing you have a slot-A chip there yes? it could be an original thunderbird (they were slot chips with 256k on die fullspeed l2 cache) or a "classic" slot-A (512k off die l2cache which runs on a divisor of the cpu speed ie 1/2 1/3 2/5. There is a little proggy called mathlon which you still may be able to find, it allows you to change the divisor for the L2 cache, you will need it at 2/5 to get any higher, but the upper end for the slot-A's was 1000, so you don't have far to go there. I'm guessing you are running 100X8.5 for 850mghz right? so you could maybe try 110X8.5. If i remember correctly, the best performance i got from mine was 110X9 for 990, but changing the multiplier on that chip requires some difficult soldering, or the use of a gold finger device which may be very difficult to find these days.



J.

[RoadWarrior]

If it's a socket A chip, then you might get 1050 out of it with a good cooler, just by banging the bus up to 133Mhz instead of 100. You will probably need to alter default voltage to do this by means of "the pencil trick" on the L5 bridges. This will allow you to set the default voltage higher to allow more stability.

i) Collect up some pencils, get a multimeter, find the one that is most conductive by testing on the ohms range with the multimeter.
ii) Sharpen it up nice and sharp, you might need to rub it on fine sandpaper to get a nice smooth sharp tip that will not crumble.
iii) Look at your CPU, the bridges to the left at the bottom are the voltage bridges, we are playing join the dots on these.
iv)pencil in between the dots on the burned out bridges, taking care not to cross connect any. Connecting all the dots gives you the highest available default voltage of 1.85V
v) test with care. If it doesn't work, or the CPU runs unacceptably hot, just rub the pencil off with your thumb or do a thorough clean up with alcohol.

I can't remember what brand of pencil worked best for me, I do remember that the common "Sandford Eagle" brand was useless for this though.

regards,

Road Warrior

edit: By the way, propelling pencils most often have polymer based leads these days that are not very conductive at all, so don't go assuming you've got the most kickass pencil for the job just because it cost you $5.

[welshexport]

;) Thanks for the advice,,but it seems a lot of work just to bump it up by that much as I've already got the cooler I might as well invest in a new chip,,,maybe the AMD 1600,,,they're knocking them out for around 45 Euro's and it should be a straight swop hope-fully,,,,,once again thanks for the info

[gazzrawly]

my old Duron 850mhz overclocked to 200mhz FSB X6 = 1260mhz @ 1.875Vc...Impressive huh ;) i think 1.2ghz shouldnt be too ahrd out of that chip...but u MUST unlock the cpu in order to gain this sort of FSB increase ... Link ALL THE L1 bridges with pencil....provided ur moo supports multiplyer switching, fsb overclocking and overvolting on the CPU, ur overclock should easily be able to get 1150mhz+ and with a bit of luck 1200mhz+ ;)


--Note : the dead duron in my rig isnt actually dead....just doesn't decompress jpegs properly and that wasnt due to voerclocking, that was due to a dodgy motherboard :)

[welshexport]

:) Once again thanks for your help I've just got some more info on my CPU///CPU Properties///does this info mean that it will be easier to over clock the chip as I said I'm new to this but am willing to learn I've got nothing to lose if I knacker the CPU then I'll have to get a new one,,,thanks again,,,,,a small programme called AIDA 32 supplied this info as well as plenty of overclocking sites cheers

CPU Type AMD Duron, 850 MHz (4.25 x 200)
CPU Alias Spitfire, Athlon Lite
CPU Stepping A2
L1 Code Cache 64 KB
L1 Data Cache 64 KB
L2 Cache 64 KB (On-Die, Full-Speed)

CPU Physical Info
Package Type 453 Pin PGA
Package Size 4.95 cm x 4.95 cm
Transistors 25 million
Process Technology 6Mi, 0.18 um, CMOS
Die Size 100 mm2
Core Voltage 1.6 V
I/O Voltage 1.6 V
Typical Power 24.5 - 37.2 W (depending on clock speed)
Maximum Power 27.4 - 41.5 W (depending on clock speed)

CPU Manufacturer
Company Name Advanced Micro Devices, Inc.
Product Information http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118,00.html

[P2P]

Originally posted by welshexport
[B
CPU Type AMD Duron, 850 MHz (4.25 x 200)

[/B]


i think that it will be 8.5x100 not what is reported