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Why do no modern-day accelerators exist for the PC?

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willmurray461

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I was just thinking about buying a 386 to 486 upgrade for one of my machines, and realized that it would be really nice if there were modern-day accelerator boards for the PC (8088, 286, 386, etc.). Tons exist for the Commodore Amiga, and now one exists for the Apple II, but none for the PC. I find it strange, given that the PC is the most successful platform of them all. I understand that the difference between the PC and the Amiga, for example, is that you can easily and affordably buy a much more powerful PC to replace your old one, but powerful Amiga's are much harder to find and much more expensive. However, is it incorrect to assume that there is still a large market which would be interested in early x86 processor upgrades?
 
I'd think most folks would just buy a newer/faster system. It would almost undoubtedly be the cheaper option nowadays. The folks wanting an accelerator are probably more likely to want a vintage one. Even given the relative scarcity of vintage PC accelerators, they're still way more common than at least Apple II accelerators -- I don't know enough about the Amiga world to know if original Amiga accelerators are rarer than PC accelerators.
 
PC accelerators went the way of the dodo when inexpensive import motherboards became available. Sure, you could pay a pile of money to put a 80286 accelerator into your 5160, but it wouldn't have half the performance or compatibility of a "Baby AT" motherboard drop-in
 
PC accelerators only survived as long as they did because of busted corporate purchase approval processes. A new computer would require going through layers of bureaucracy while an expansion board was immediately approved.
 
Chuck(G) said:
...Sure, you could pay a pile of money to put a 80286 accelerator into your 5160...
Click to expand...
I was thinking more along the lines of the Intel Inboard 386/PC, or the 486SLC2 upgrades for 286's, things with greater performance boosts.
glitch said:
...they're still way more common than at least Apple II accelerators...
Click to expand...
I guess for now. But I heard they're accepting pre-orders for new TranswarpGS accelerators. Apparently, they were able to reverse engineer the PAL's.

I understand that buying a new machine or replacing the motherboard is much easier and cheaper. However, I just don't like replacing the original motherboard. I might be totally irrational or crazy on this, but I feel that others might share the same stance. I also really enjoy the aesthetics of the IBM PC and PS/2 systems, but would like to run slightly more interesting software on them. And yes, I know that putting a 486 in an 8MHz mobo with 150ns memory is a bit counter intuitive, but I find it fascinating nonetheless. Also, I wonder how difficult it would be to create a clone of the Intel Inboard 386/PC. If I were to pick one accelerator to be remade, it would probably be that. Just looking at it now, it seems to have at least 14 HAL programmable logic chips. which I assume would all need to be reverse engineered. It's also a 6 layer board, which I'm sure would complicate things.
 
I think it comes down to market. Consumer upgrades is probably a tiny audience plus today's level of tech integration and pace makes it very hard to attempt anything worth a serious business.
 
krebizfan said:
PC accelerators only survived as long as they did because of busted corporate purchase approval processes. A new computer would require going through layers of bureaucracy while an expansion board was immediately approved.
Click to expand...

Also, the tax system. When I bought my PC for business use, the depreciation schedule was something like 10 years for data processing gear. Obviously, any corporate entity wants to take the depreciation deduction as long as possible. Selling the older gear as used requires yet another layer of bureaucracy.

It wasn't until much later that computer gear was recognized as "consumable". There are other tax schemes still in existence that are equally wacky.
 
There was a thread about running a 5x86 in an Inboard here: http://www.vcfed.org/forum/showthread.php?57033-running-5x86-cpu-in-IBM-5150-with-Inboard-386

The big problem is you still have to go through the ISA bus, so the speed increases of using faster CPUs are minimal.

In baby-AT form compatible systems, the common thing to do was just replace the entire motherboard. There were AT form motherboards up to the Pentium 1/AMD-K6 range, and added the ability to use PCI, faster on-board I/O, and more RAM.
 
People tended to upgrade back then because of new technology and not just for a faster processor. VLB, PCI, AGP, SATA, faster RAM types were things people eventually wanted to upgrade to.

There were companies making AT for factor boards well into the Pentium 2/ K6-3+ era for drop in replacement targeted at home users. For those who were real cheap companies did make CPU upgrades for older systems. I have some K6-2 upgrade chips with their own voltage regulaters that drop into old Socket 5 Pentium motherboards. People also purchased 486 CPU upgrades from Evergreen.

These days a PCIE drop in CPU card would be much more expensive and come in so late that just buying a new system would be cheaper and faster.
 
krebizfan said:
PC accelerators only survived as long as they did because of busted corporate purchase approval processes. A new computer would require going through layers of bureaucracy while an expansion board was immediately approved.
Click to expand...

Lots of truth to that. While working for the feds, we always had money for repairs and upgrades but new purchases were normally "budgeted" items (except if you were the boss).
 
Chuck(G) said:
It's also why Federal surplus auctions are so great. Stuff gets put in storage for years until it's finally sold as part of a surplus lot.
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Yes, those auctions were a great thing, but we were not permitted to offer a bid in our own bailiwick, legally. A good while back a new agency head decided that personally owned weapons and odd ball agency ones were a thing of the past. Some bonded outfit was commissioned to purchase the old agency weapons, at what amounted to a ridiculously low price, who, in turn, offered them back to the original custodian for an equally ridiculous high price.
 
I LOVE my Intel InBoard/386 PC. It has a 4MB daughter card (for a total of 5MB of extended RAM). I dropped in a pin-compatible 486 CPU (took less than 5 minutes) and a driver to get to 486 class CPU performance with my 5160 system board, but there are limitations. For example, there's no way around the 8-bit system bus, and, the oscillator that comes stock on the InBoard throttles my Cyrix CX486DRX2-20/40GP 40MHz CPU down to a maximum speed of 33MHz (I'm too timid to take a solder gun to the InBoard to replace the oscillator seeing how rare and expensive they are). Also, the Cyrix CX486DRX2 CPU is limited to only 1MB of on-boards cache as opposed to standard 486DX CPUs. I did replace the HDD with a pair of CF drives using an XT-IDE adapter which removed any slow HDD bottlenecks.

Nevertheless, the baby rocks at 33MHz and I can run all DOS and Windows 3.1 programs (in enhanced mode) with very good performance.

Mike

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PC CPU upgrades were REALLY popular for IBM PS/2s. They were very expensive new so an upgrade was seen as a cost effective solution to keep them in service for longer. I can't imagine something like the AOX MicroMaster 386 that came in one of my Model 50zs was cheap new, but it was cheaper than completely replacing that 50z that cost a fortune new in 1987.
 
The Inboard 386/PC is a wonderful accelerator. I’ve got one in one of my 5150s, and I will never part with it :)
 
I have an Inboard 386/PC too, as well as a Cyrix 486DRx2 16/32 to go with it. I recently bought a 5150 to put it in. Can't wait to pick it up! I just wish I could get one of those 1/2/4MB piggyback boards. Sometime, I might try mapping the pinout of the expansion connector and maybe make my own board that works with 72 pin SIMMs, but I've got a lot of learning to do before that can happen. If only someone with the proper knowledge and experience could do it. I've also been trying to find a suitable 386-486 upgrade for my decked-out PS/2 model 80. It's got 25MHz 386DX & 64KB L2 Cache, 16MB RAM, SCSI/A w/ 2MB Cache, 8514 w/ 1.5MB & 8514 display, Sound Blaster Pro 2 MCV, and 2x CD-ROM. I really wish I picked up one of those Reply power boards when they were on eBay. It was a bit pricey at $300, but if it were still listed I'd probably still buy it. I also missed a Kingston McMaster 486 for $50 simply because I forgot to bid on it. I'm pretty sure someone else on the forums bought it :p. I've also got this PS/2 486SLC upgrade for the models 50 and 60. I'd like to try it out in an AT, but I need to create a socket adaptor for it first. Luckily, that requires no components, only traces, so it should be easy to design. Worst come to worst, I'll just use it as it was intended in my Model 60.
 
Agent Orange said:
Lots of truth to that. While working for the feds, we always had money for repairs and upgrades but new purchases were normally "budgeted" items (except if you were the boss).
Click to expand...

We have done things both ways. Sometimes there was "capital" budget and we could buy new machines, but might end up parting them for spares because it was easier than building a new machine. More often we had money for spares so we bought extra and built new machines, especially stuff like PDP-11's, from them
 
I find it hard to see how you could make an accelerator card for a modern PC. These processors run really fast. The boards are tuned to get maximum speed from the RAM. Anything that would be faster would be a complete new board and not something that could be tacked on. The only thing I can think of is specialized FPGAs for such things as bit mining or video processing.
It would be difficult to share the resources of today's boards without decreasing the performance, rather then increasing.
Dwight
 
Dwight Elvey said:
I find it hard to see how you could make an accelerator card for a modern PC. These processors run really fast. The boards are tuned to get maximum speed from the RAM. Anything that would be faster would be a complete new board and not something that could be tacked on. The only thing I can think of is specialized FPGAs for such things as bit mining or video processing.
It would be difficult to share the resources of today's boards without decreasing the performance, rather then increasing.
Dwight
Click to expand...

Like these FPGA boards?

https://www.xilinx.com/products/boards-and-kits/accelerator-cards.html

in any case in general it is rare to max out the CPU on many modern boxes. It normally the Disk that is the bottleneck, so I guess the current equivalent of of the old accelerator boards is your SSD
 
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