Anyone remember OCing back in the DOS days?

VirtualLarry

No Lifer
Aug 25, 2001
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I just saw an ad from PKWARE, and it got me thinking.

I remember doing stability testing back in the DOS days, to test my overclock, by using PKZIP to unzip several large archives (using the -386 extensions), in a batch file loop. It would give you a CRC error if there was a failure. Back then, it was the best stability tester, much like Prime95 is today.

Does anyone else remember doing that?
 

VirtualLarry

No Lifer
Aug 25, 2001
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Oh, I almost forgot - that was with the data copied to a RAMdisk, for maximum performance and to test out the RAM too.
 

Tempered81

Diamond Member
Jan 29, 2007
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hey larry i remember pkzip being one of the first pieces of software i became familiar with. But that was with my first cmoputer = a 486, probably not as old as your first 4mhz or 7mhz ti/ motorola/ tandy/ intel. :)
 

Idontcare

Elite Member
Oct 10, 1999
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I vividly remember the pre-windows era, but alas I did not get into the OC scene until I had my Cyrix in hand circa 1996 (OC'ed from 120MHz stock to 133MHz, wickedly heat limited IRC).

Even at that I doubt it was actually a stable overclock as the only "stability" checks I did back then was to run some filters in Photoshop and see if she locked up or crashed.
 

Zap

Elite Member
Oct 13, 1999
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I had access to some testing software. We had software for "burn in" that supposedly tests the CPU and RAM, among other things.

My first computer in 1990 was a 386 DX 25 overclocked to 27MHz with a different crystal. It was, ahem, "factory overclocked" because the vendor sold them that way in order to "win" reviews against other vendors in Computer Shopper. It's still a trick used to this day with motherboard manufacturers that will surreptitiously set the CPU FSB one or two MHz higher so that their board will be at the top of any benchmark against a competitor.

486 based systems got pretty easy to overclock in the heyday with boards having tons of jumpers onboard. I remember having OPTi and ULi chipset VLB boards (VESA Local Bus) with jumpers for 25/33/40/50MHz FSB, 1/2/3/4x multipliers and various voltages. The first CPU I killed was a 486SX25 that I tried overclocking. Was running it at 40MHz when it suddenly locked up. It was dead from that point on. No great loss as Pentiums were already out, so this was just an old CPU we had gotten for free and were screwing with (me and NowhereMan, for those that remember permanently banned members).

Got better with socket 7. OMG, the TX chipset Shuttle HOT-557 was probably the best, with ettings available in BIOS and a jumper block (replaced by dip switches in later boards) for all the BUS speeds and multipliers overriding the BIOS. I think this was the first Anandtech review I read, BITD. These rocked with any Intel CPU. Pentium 75 was an easy 90MHz. Pentium 90 was an easy 100MHz. Pentium 100 was an easy 120MHz. 120=133, 133=150, 150=166. Sometimes if you lucked out you can jump two speed grades stably. The best were the Pentium MMX chips. They were available for the desktop in 166/200/233MHz models, and a 266MHz notebook model. They were such easy overclocks that many unscrupulous vendors sold Pentium MMX 166 chips in systems overclocked to 233MHz, and there was even a cottage industry around "remarking" the chips meaning sanding the print off it and printing the markings from a faster CPU on it. Since the bus and multiplier were conpletely controlled by the motherboard, it was impossible for a normal user to tell that they were paying extra for a slower CPU. I once even got a Pentium MMX 233MHz running at a whole 300MHz on a super 7 board, but it suffered an early, mysterious and sudden death for some reason. :shocked: Ah well, belonged to a friend of mine and he got it for really cheap since we were already at faster slot systems.

I moved on eventually to an Asus P5A board that was an ALI chipset or something, with a bunch of FSB speeds. It was my first ATX board and a rockin' "Super 7" board with an overclocked AMD K6-2. I even had a Matrox M3D 3D accelerator and a Matrox G200. This was probably my last machine that I regularly booted into DOS, because Quake 3 came out and my life changed. :p
 

cboath

Senior member
Nov 19, 2007
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I remember talking a friend of mine into getting a 486DX50 machine instead of a 486DX2-66. He (and the salesman) were saying how the 66 should be faster. I said, trust me. He bought it, and his rendering times in old 3d studio R2 (dos) were faster than the other couple guys in the class who bought the 50. You couldn't overclock that unless you tried to set a multiplier of 2 on the board via jumpers and with cooling available at that time, it wasn't going to happen. It was another 2 years or so before they started having DX4 boards and chips. I don't know if there ever was a 486-100DX2 There were at the DX4, i know that.
 

Fox5

Diamond Member
Jan 31, 2005
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I remember the turbo button on computers. I didn't think it actually did anything.
Honestly, I didn't consider overclocking until I heard about Athlon and the golden fingers, and didn't overclock until I got an nforce2 board. (then went back and tried it with older VIA boards, only to find that nforce2 pretty much was the first good overclocking board for the athlon xp)
 

Spook

Platinum Member
Nov 29, 1999
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Old school OCing... I think the 1st one i remember was the easy AMD 486-120, OC to 133 if i remember right...
 

Amaroque

Platinum Member
Jan 2, 2005
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Not an overclock, but I rember adding 2MB if RAM to my 386SX 16MHz. It was a LOT faster going from 2MB to 4MB! It had windows 3.0, but most stuff was still done in DOS back then.

My first real OC was taking a P54c from 100MHz to 120MHz (from 1.5x 66, to 2x 60).
 

mizzou

Diamond Member
Jan 2, 2008
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I just remember making boot disks to make my computer faster and hitting the turbo button

lol
 

biostud

Lifer
Feb 27, 2003
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I remember overclocking was done pushing the "turbo button" which switched the 386SX between 16 and 25Mhz :p
 

myocardia

Diamond Member
Jun 21, 2003
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My first overclock was running my 25 Mhz 486SX @ 33 Mhz. I've overclocked every CPU I've owned since. I never tried overclocking any of my earlier systems, because of having to change crystals, but changing jumpers on the 486's was pretty easy.
 

Regalk

Golden Member
Feb 7, 2000
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My first computer was a 386 SX25 and had no clue about overclocking. Instead I messed with the internal speakers wiring multiple hard drives, fax modems to get on to the internet - yeah that was fun when I got successful connections and was able to login to some BBS or whatever. Those 5 1/4 floppies were a joke
 

Marty502

Senior member
Aug 25, 2007
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I overclocked my 486 DX4 to 120 Mhz, from 100 Mhz stock. At 133 Mhz it wouldn't boot up. Loved it. :D

I just used some common sense and the mobo manual. Like "Hey, so if I move this little cap thing from here to here it will be faster? Yay :D"

It worked! And I'm pretty confident I'll be alone in this but...

I overclocked my 2MB Trident card too! There was an utility to raise the clocks. I can't remember how much I got out of it, but Quake became playable. On a 486!
 

fritzfield

Senior member
Mar 4, 2003
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I think DOS was dead when my $72 stock Celeron 300 at 66 FSB would run as a 450 at 100 FSB on an Abit BX-6. I thought I was pretty cool.
 

sgrinavi

Diamond Member
Jul 31, 2007
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I moved many jumpers around back in the day.. I think my first was a 386, but I don't recall... either way I never tested for stability... If it booted it was usually good to go
 

taltamir

Lifer
Mar 21, 2004
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Originally posted by: CTho9305
Originally posted by: BlueWeasel
I didn't even know it was possible to OC back in DOS. :Q

Jumpers on the motherboard, or swapping out clock crystals :).

swapping crystals? sounds like a fantasy RPG :p...

Are you being serious here? (i know you meant the pizo-electric quartz crystals, I just didn't know you could swap them.)
 

Mir96TA

Golden Member
Oct 21, 2002
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My First O.C was
286 9Mhz to 12Mhz by changing Crystal and ADDING LONG 2 inch Heat Sinker on it,
Guess what it was fastest 286 and made by AMD
 

SinxarKnights

Member
Dec 16, 2007
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My first OC was on a win95 machine. I had no clue what I was doing and popped the multiplier from 5x to 10x and fried the CPU! :) That was with jumpers on the MB and it wasn't even mine.
 

mruffin75

Senior member
May 19, 2007
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My first "overclock" if you can call it that, was to increase the speed of my Commodore Amiga 500 from 7Mhz to 14Mhz...

Not really simple... had to buy the upgraded 14Mhz version of the 68000 (back in those days, about $20 or so), build a little halving circuit and get the signal from another chip at 28Mhz..

And to switch between 7Mhz and 14Mhz you pressed a switch on the outside of the case which grounded the halt pin on the CPU, then switched frequencies, then let go of the halt switch...worked about 99% of the time...
 

mruffin75

Senior member
May 19, 2007
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Originally posted by: Mir96TA
My First O.C was
286 9Mhz to 12Mhz by changing Crystal and ADDING LONG 2 inch Heat Sinker on it,
Guess what it was fastest 286 and made by AMD

You mean the fastest 286 ever?? I had a 16Mhz 286...???
 

Zap

Elite Member
Oct 13, 1999
22,377
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Originally posted by: cboath
I remember talking a friend of mine into getting a 486DX50 machine instead of a 486DX2-66... I don't know if there ever was a 486-100DX2 There were at the DX4, i know that.

AFAIK there were no DX2-100 chips. The DX4 chips actually ran on a 3x multiplier normally, with 4x available (but seldom used unless on super old boards).

To put this into more modern terms for the noobs to understand, it is like the difference between a Core 2 Duo E6700 and E6750. Pretty much same MHz, but one ran the bus faster.

With the 486 chips not only the board/bus ran faster, but the VLB (VESA Local Bus for video cards) and the memory ran at the CPU's external MHz, thus ran faster.

Originally posted by: Regalk
Those 5 1/4 floppies were a joke

Yeah, but they could be "overclocked" by buying double density disks and formatting them high density. With the 5¼" disks you used a hole punch to cut a notch opposite of the write protect notch. With the 3½" disks I ended up buying a custom floppy hole punch. It was this cast aluminum deal with a lever. Put the disk in, push down lever, a small hole appeared opposite the write protect.

Basically the floppy drive had a pin in those locations to tell it "yes/no can format HD."

Originally posted by: Marty502
I overclocked my 2MB Trident card too! There was an utility to raise the clocks. I can't remember how much I got out of it, but Quake became playable. On a 486!

I first got into overclocking video cards with my Matrox Millenium G200 8MB card. I found out how to do a timedemo in Quake 3 and I got... 14FPS (this was using an AMD K6-2 overclocked to 350MHz or something). Lowering quality settings in the game helped greatly. Then, I discovered a DOS utility that allowed me to make changes to the video card. It had a TON of settings, not like current video card overclocking which is just GPU and RAM clocks. This allowed for those clocks, plus around 8 or 12 different latencies to be set. I ended up with around 48FPS in Quake 3, which was great until one of my buddies got a Voodoo Banshee and squashed my score.

Originally posted by: taltamir
swapping crystals? sounds like a fantasy RPG :p...

Are you being serious here? (i know you meant the pizo-electric quartz crystals, I just didn't know you could swap them.)

They were enclosed in these little metal packages with two legs, and you would desolder the old one and solder in the new one... and pray.

Originally posted by: mruffin75
You mean the fastest 286 ever?? I had a 16Mhz 286...???

I think NEC had gotten a license for making 286 chips and were releasing them up to 20 or 25MHz.