LGR 486 Update! 83MHz Pentium Overdrive CPU
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Date: 2022-04-14
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Comments and reviews: 10
Jean
i buy and use one for time back then, it was verry deceyving result not for bug. -
but it was like some people who cant think and speack in the same time.
i even switch my computer board for its, since it was not compatible whit the amd 486X4-
limit to 66mhz in the bios despicte theyre was a pin setup for 25, 33, and 40mhz. -
so y switch the bord just for the intel CPU. never work as espected, verry silent as noise go. -
i like that but slow, SLOW as melasse half of the time. never solve the problem its stop to think-
every minutes or so. no crash just like the computer stop what ever y do, take a segonde break! than resume-
what ever i was doing. someone since then tell my that was the ecc in my 72 pin chip memorie that was incompatible? -
i never play games whit it y was working in adaptiong TINman a dos program for the blind -
trying to adapt it for windows 95 16 bits, a program i create wen working at Texas intrument in your corner of the planet, i help create a non APL version of the work sythesis a venture system betwen AT&T and texas instrument in voice synthese. Texas intrument voice synthese chip wheyre create whit APL library and register, i finish the years whit a 486X4 100 (push to 118mhz) since my new board was faster whit AMD its, a lots faster. after that years y switch to the pentium 60. they sell them a base price for the math bug, never ave problem whit the bug still a pentium board original P60-
for 50$ i still ave it somewheyre in a molded resin box, i mold a lot of my old cpu in resin. not place to display them-
now. since i am renovationg. ok long renovation i start 5 years ago and still not finish. houps! i am retiry, we alwais a someting to do but slowly.
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i buy and use one for time back then, it was verry deceyving result not for bug. -
but it was like some people who cant think and speack in the same time.
i even switch my computer board for its, since it was not compatible whit the amd 486X4-
limit to 66mhz in the bios despicte theyre was a pin setup for 25, 33, and 40mhz. -
so y switch the bord just for the intel CPU. never work as espected, verry silent as noise go. -
i like that but slow, SLOW as melasse half of the time. never solve the problem its stop to think-
every minutes or so. no crash just like the computer stop what ever y do, take a segonde break! than resume-
what ever i was doing. someone since then tell my that was the ecc in my 72 pin chip memorie that was incompatible? -
i never play games whit it y was working in adaptiong TINman a dos program for the blind -
trying to adapt it for windows 95 16 bits, a program i create wen working at Texas intrument in your corner of the planet, i help create a non APL version of the work sythesis a venture system betwen AT&T and texas instrument in voice synthese. Texas intrument voice synthese chip wheyre create whit APL library and register, i finish the years whit a 486X4 100 (push to 118mhz) since my new board was faster whit AMD its, a lots faster. after that years y switch to the pentium 60. they sell them a base price for the math bug, never ave problem whit the bug still a pentium board original P60-
for 50$ i still ave it somewheyre in a molded resin box, i mold a lot of my old cpu in resin. not place to display them-
now. since i am renovationg. ok long renovation i start 5 years ago and still not finish. houps! i am retiry, we alwais a someting to do but slowly.
reply
Trev0r98
I don't understand this. Back in 1995 Descent ran just fine on my intel 486 DX-2 66-based desktop PC (8 MB 70ns RAM - 2 x4 MB SIMMs. I got around 40 fps, very busy battle scenes, and that was at 1024x768, full -eye candy- graphics mode. even in multiplayer mode, over a 14. 4K modem. -40 fps, like it was on rails. I had a pretty nice 15- CTX CPS-1560 CRT digital glass monitor, -60Hz max refresh rate. Maybe the excellent performance was mostly due the system having onboard VLB video (-Vesa Local Bus-. The chipset was Cirrus Logic CL-GD5428, and it had 1 MB dedicated VRAM. When I upgraded from the DX-2 66 to the AMD 5x86-133 MHz CPU, the fps jumped up to 60 fps (which is all that my 60Hz CTX CRT monitor could handle. Good times. Jeez, I miss the -Go-Go '90s- so bad. lots of LAN parties & hot BBS babes.
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I don't understand this. Back in 1995 Descent ran just fine on my intel 486 DX-2 66-based desktop PC (8 MB 70ns RAM - 2 x4 MB SIMMs. I got around 40 fps, very busy battle scenes, and that was at 1024x768, full -eye candy- graphics mode. even in multiplayer mode, over a 14. 4K modem. -40 fps, like it was on rails. I had a pretty nice 15- CTX CPS-1560 CRT digital glass monitor, -60Hz max refresh rate. Maybe the excellent performance was mostly due the system having onboard VLB video (-Vesa Local Bus-. The chipset was Cirrus Logic CL-GD5428, and it had 1 MB dedicated VRAM. When I upgraded from the DX-2 66 to the AMD 5x86-133 MHz CPU, the fps jumped up to 60 fps (which is all that my 60Hz CTX CRT monitor could handle. Good times. Jeez, I miss the -Go-Go '90s- so bad. lots of LAN parties & hot BBS babes.
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James
As I've mentioned in one of your blurbs videos, these processors can only run faster than the frontside bus speed (33Mhz in this case) when data is in cache. Otherwise, if it has to page data from RAM then it is going to stall and not do anything while data arrives to do more work on. Cache operations are typically invisible to the user but can be assisted by the programmer or the compiler. But anything that needs to move more than 32kb (the cache in this processor) of memory from RAM it has to page it in which incurs stalls on the processor and the computer does nothing in those intervals. Faster front-side bus speeds dramatically improve the perceived computer performance for games because memory runs dramatically faster (in the case of 50 or 66Mhz chip/FSB base speeds.
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As I've mentioned in one of your blurbs videos, these processors can only run faster than the frontside bus speed (33Mhz in this case) when data is in cache. Otherwise, if it has to page data from RAM then it is going to stall and not do anything while data arrives to do more work on. Cache operations are typically invisible to the user but can be assisted by the programmer or the compiler. But anything that needs to move more than 32kb (the cache in this processor) of memory from RAM it has to page it in which incurs stalls on the processor and the computer does nothing in those intervals. Faster front-side bus speeds dramatically improve the perceived computer performance for games because memory runs dramatically faster (in the case of 50 or 66Mhz chip/FSB base speeds.
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Russ
The AMD 486 cpus where incredibly overclockable. You 486dx2-66 would easily overlook to dx2-80 and in many cases as a dx2-100.
Back in the day I'd buy amd 486sx-25's and overclock them to 486sx-50.
As for that 586 overdrive, it will also overclock.
As a side note, it had 16kb of L1 data cache AND 16kb of L1 instruction cache. Not being able to set it to write-back does not disable it. Most 486 motherboards didn't report instruction cache nor did most benchmark software. The 486 had only 8kb of SHARED data and instruction L1 cache. The overdrive has 16kb of data and another (separate) 16kb of instruction L1 cache.
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The AMD 486 cpus where incredibly overclockable. You 486dx2-66 would easily overlook to dx2-80 and in many cases as a dx2-100.
Back in the day I'd buy amd 486sx-25's and overclock them to 486sx-50.
As for that 586 overdrive, it will also overclock.
As a side note, it had 16kb of L1 data cache AND 16kb of L1 instruction cache. Not being able to set it to write-back does not disable it. Most 486 motherboards didn't report instruction cache nor did most benchmark software. The 486 had only 8kb of SHARED data and instruction L1 cache. The overdrive has 16kb of data and another (separate) 16kb of instruction L1 cache.
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Pete
When my parents' 486DX with an overdrive's chip finally died it had not occurred to the man who originally had built the system to swap the 486DX back in again. It was too late when they gave me the hardware to look at because they did not ask me about it until they had bought a whole new computer. By the time they had me look at it they had become used to a Pentium. Oops. (And for the record it was because my brother-in-law got me Descent and it was not running as well as it did on his computer that I got them the accelerated chip)
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When my parents' 486DX with an overdrive's chip finally died it had not occurred to the man who originally had built the system to swap the 486DX back in again. It was too late when they gave me the hardware to look at because they did not ask me about it until they had bought a whole new computer. By the time they had me look at it they had become used to a Pentium. Oops. (And for the record it was because my brother-in-law got me Descent and it was not running as well as it did on his computer that I got them the accelerated chip)
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Fuzzy
1) The first computer I owned was a Packard Bell 486 SX33 with a tape drive and Windows 3. 11 (Windows for Workgroups. I bought a computer to design model airplanes which I had been drafting by hand until then. So I called AutoDesk about getting AutoCad. They told me that I absolutely needed a 486 DXII to run AutoCAD at all. So I bought one for $400. Everything was $400 back then. I upgraded the RAM. $400. 00. I bought a larger HD. $400. 00. Later I realized that for what I wanted to do I could have run AutoCAD on a 386.
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1) The first computer I owned was a Packard Bell 486 SX33 with a tape drive and Windows 3. 11 (Windows for Workgroups. I bought a computer to design model airplanes which I had been drafting by hand until then. So I called AutoDesk about getting AutoCad. They told me that I absolutely needed a 486 DXII to run AutoCAD at all. So I bought one for $400. Everything was $400 back then. I upgraded the RAM. $400. 00. I bought a larger HD. $400. 00. Later I realized that for what I wanted to do I could have run AutoCAD on a 386.
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purringc
Man, I lusted after this upgrade when I was in high school. Had a Packard Bell and I loved upgrading it. Never got this processor. Ended up getting some sort of cpu upgrade from a company called Evergreen. All in all, I upgraded the CPU, RAM, HDD, CD-ROM drive, mouse, and keyboard. What I learned from all those upgrades? Well, in the end, they were never worth it. At least, not for that type of computer. After so much time goes by, you just need to buy or build a new computer.
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Man, I lusted after this upgrade when I was in high school. Had a Packard Bell and I loved upgrading it. Never got this processor. Ended up getting some sort of cpu upgrade from a company called Evergreen. All in all, I upgraded the CPU, RAM, HDD, CD-ROM drive, mouse, and keyboard. What I learned from all those upgrades? Well, in the end, they were never worth it. At least, not for that type of computer. After so much time goes by, you just need to buy or build a new computer.
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Jerry
I had a vlb system with a trident 1mb video card and intel 486dx2 66mhz cpu. I remember duke 3d just barely able to run at 320x200 res. Quake was a slide show. Doom ran fine. I think for quake and duke you need minimum pentium 90. The pentium had two math pipelines and I remember carmack talking about coding for those two pipelines so that quake could run in real time. Michael Abrash and John Carmac did a great job optimizing the code.
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I had a vlb system with a trident 1mb video card and intel 486dx2 66mhz cpu. I remember duke 3d just barely able to run at 320x200 res. Quake was a slide show. Doom ran fine. I think for quake and duke you need minimum pentium 90. The pentium had two math pipelines and I remember carmack talking about coding for those two pipelines so that quake could run in real time. Michael Abrash and John Carmac did a great job optimizing the code.
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pumelo1
Bestest -overdrive- procesor on socket 3 was AMD DX5-133Mhz /Am5x86-P75/ Nobody beat this processor! Was better than socket 4 Pentium 50/55 on 5volt and same rate like socket 5 Intel Pentium 75 I used this processor on my MB, but this MB bios and jumpers can carry only DX4-120Mhz, but also i this lower frequency was benchmark on dhrystone better than Pentium 75 in whetstone was on 85% of Pentium.
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Bestest -overdrive- procesor on socket 3 was AMD DX5-133Mhz /Am5x86-P75/ Nobody beat this processor! Was better than socket 4 Pentium 50/55 on 5volt and same rate like socket 5 Intel Pentium 75 I used this processor on my MB, but this MB bios and jumpers can carry only DX4-120Mhz, but also i this lower frequency was benchmark on dhrystone better than Pentium 75 in whetstone was on 85% of Pentium.
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Dastractionwolf
I just keep thinking like. Let's say I didn't have documentation, just the demo disk and I had no knowledge of hot to instal a CPU. I can't run the disk on my only pc and remove the cpu at the same time. Today I'd snap photos of the tutorial with my smart phone. But I could see myself trying to memorize the whole process before trying it. Which isn't too bad except maybe the jumpers.
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I just keep thinking like. Let's say I didn't have documentation, just the demo disk and I had no knowledge of hot to instal a CPU. I can't run the disk on my only pc and remove the cpu at the same time. Today I'd snap photos of the tutorial with my smart phone. But I could see myself trying to memorize the whole process before trying it. Which isn't too bad except maybe the jumpers.
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