First post, by clueless1
- Rank
- l33t
Lots of us here grew up through a variety of DOS generations, where system speed was critical to good gameplay. In the 386 days, we were lucky if the latest games ran well on our systems. But within a generation, those same games played too fast on our 486-class PCs.
Today, those of us with retro PCs try to recapture as much of that nostalgia as we can, but if you're within a space or financial constraint, it's not always possible to have a 386 for 386 games, a 486 for 486 games, and a Pentium-class system for its generation of games.
Phil from philscomputerlab.com made a very nice video demonstrating how to build a system that can be many generations in one box. Phil also set up the Ultimate VGA Benchmark Database Project so that members of the community could add their own results. This benefits everyone!
Led by advice from forum members Tertz and gdjacobs, I pulled what I felt were "good representatives" for each type of old CPU out of Phil's VGA Benchmark Database, from the 100Mhz 486 down to the slowest system represented, an i386DX-16. These results are now our guideposts as we determine where our Pentium-class and higher processors fall when we disable various caches to intentionally drop performance. For this purpose, I set up a Google Sheets page to add results for CPUs with all caches enabled AND with caches disabled. In the spreadsheet the guidepost results are indicated in red text.
So here's how this works: If you don't already have this on every DOS machine you own ( 😉 ), download Phil's VGA Benchmark kit here. For instructions, see his thread linked a couple of paragraphs up. Now download gerwin's Setmul utility here. Instructions are in the link. Setmul will allow you to disable the L1 cache on any x86 processor from the 486 on up and allows disabling L2 cache on K6 Mobile and VIA C3 chips.
Benchmark your systems with all caches enabled, as well as with whatever combinations of caches you can disable. In the spreadsheet, there are some results there that give examples with L1 cache disabled, L2 cache disabled and both L1 and L2 caches disabled. For this test, we are running 3DBENCH 1.0c (aka 3DBENCH2), PCPBench, Speedsys, and Doom. Speedsys is in the Speedsys folder in Phil's kit. I left out Quake because for our purposes, it is not relevant--an intentionally slow system would not be running it anyway. In the event your slowed down system is running at 286 or slower speeds, substitute 3DBENCH 1.0 (it is in the 3DBENCH folder in Phil's kit). As you can see from the Pentium II results at the bottom of the spreadsheet, 3DBENCH 1.0c does not scale well at very slow speeds. Version 1.0 should do the trick here. Thanks to Phil for providing that info.
I have the spreadsheet sorted by Doom results because as the only actual game benchmark, I feel it should be factored highest. Feel free to download a copy of the spreadsheet and sort it however else you'd like to.
You may access the spreadsheet here: https://docs.google.com/spreadsheets/d/1uKhCI … dit?usp=sharing
EDIT: If in the process of adding your results you accidentally muck up the spreadsheet, please post here ASAP so I can revert it to its previous revision. I've had an instance where the spreadsheet was mangled and I didn't discover it til months later. In the process of restoring the last good version, we lost results that people had added after last known good version. Thanks.
When entering results, input them at the bottom of the sheet. I will periodically resort the list. To keep the spreadsheet tidy, just report your CPU at the speed it is running (eg, AMD K6-2 170) rather than its rated speed (AMD K6-2 500). So if you are reporting multiple clock speeds with the same CPU, each of your entries will have a different CPU description. See my results on the spreadsheet for examples. The CPUs I tested were a K6-2 550 @ 166, 238, 350, 366, and 550, Pentium 120 @ 75-133Mhz, Pentium II 333 @ 133-333Mhz, a Celeron 333 (locked), and POD 200. The motherboard I used for the K6-2 includes 512KB L2, but does not support disabling the cache (so no results with L1+L2 disabled).
I'm really curious to get as many types of CPUs on this list as possible, especially some of the more exotic/rare ones. Thanks for taking the time to read!
EDIT: Now that we have a decent amount of results, I picked some common CPUs to highlight on their own spreadsheet tabs. I chose results from common and fast motherboard chipsets and graphics cards.
The more I learn, the more I realize how much I don't know.
OPL3 FM vs. Roland MT-32 vs. General MIDI DOS Game Comparison
Let's benchmark our systems with cache disabled
DOS PCI Graphics Card Benchmarks