Via Ezra-T CPUs are seemingly the most flexible because of the range of multipliers available. Using SetMul to change the multiplier and cache status.

I’ve been meaning to get hold of one for a while.

paradigital wrote on 2024-03-19, 06:47:

Via Ezra-T CPUs are seemingly the most flexible because of the range of multipliers available. Using SetMul to change the multiplier and cache status.

I’ve been meaning to get hold of one for a while.

Thank you for confirming, I’ve only today started learning about SetMul and it seems like just the ticket. I’ve spent so long focusing on new hardware that I’ve been out of the loop with regards to vintage stuff - back in the day we used the likes of MoSlo to get DOS titles running on the faster machines, it was much more crude than SetMul though.

So regarding the VIA CPUs, it looks like any of them on S370 are adjustable with SetMul but you’d advocate the Ezra T because of its wide range of multis?

Might be a challenge finding one, a cursory glance on eBay shows up only a Nehemia, and it ain’t cheap! 😳

May I also suggest "Throttle": http://www.oldskool.org/pc/throttle/DOS/

An awesome little tool that allows you to use power saving registers of your chipset to slow down the CPU. Even without multiplier adjustment, this would at least allow you to get down to 54 MHz (6.25% of the original speed), enough for some less sensitive titles. With a Pentium 75 and disabled cache, I managed to almost hit the speed of a 5 MHz 8088 CPU.

asdf53 wrote on 2024-03-19, 12:39:

May I also suggest "Throttle": http://www.oldskool.org/pc/throttle/DOS/

An awesome little tool that allows you to use power saving registers of your chipset to slow down the CPU. Even without multiplier adjustment, this would at least allow you to get down to 54 MHz (6.25% of the original speed), enough for some less sensitive titles. With a Pentium 75 and disabled cache, I managed to almost hit the speed of a 5 MHz 8088 CPU.

Interesting, thank you; I did read about that last night - some seem to have had great results, and 5MHz from a P75 is outstanding! Others have reported audio issues and choppiness, so I guess mileage will vary.

I wonder if I can use it alongside SetMul, have the CPU at 3x66 then have Throttle take it down further.

As tools like SetMul and Throttle (and others) work by adjusting registers, I'd be surprised if using two side by side would really make much difference over what the better of any set of apps can do on its own.

Dan386DX wrote on 2024-03-19, 18:25:

Interesting, thank you; I did read about that last night - some seem to have had great results, and 5MHz from a P75 is outstanding! Others have reported audio issues and choppiness, so I guess mileage will vary.

I did not have these problems on my Pentium 1 system, but I decided to test it just now on my "fast" system (Athlon 500). And indeed, the lowest setting (6.25%) did not work properly. The DOS prompt kept freezing and I got sprite flickering in one game (Commander Keen). Sound was fine. All problems disappeared with the next setting (12.5%). If you try it on your system please post your findings here.

Dan386DX wrote on 2024-03-19, 18:25:

I wonder if I can use it alongside SetMul, have the CPU at 3x66 then have Throttle take it down further.

You might also want to check out CPUSPD: CpuSpd - A Hardware Based CPU Speed Control Utility for DOS/Win9X Retro Gaming

I've been using both CPUSPD and SETMUL to throttle performance on a Pentium 4 build. I've even managed to squeak down to ~286 level performance.

Side note I had this issue with Wing Commander on a Celeron 500Mhz that I could not throttle well with DOS. I bought this PC Gamer disc that had the full version of the Windows port of the game and it works great! Can still be found pretty cheap on eBay today considering all the great titles it contains: https://x.com/banditloaf/status/1669466388518 … 0BQjhmqZkJmyAjQ

Zeerex wrote on 2024-03-19, 22:56:

Side note I had this issue with Wing Commander on a Celeron 500Mhz that I could not throttle well with DOS. I bought this PC Gamer disc that had the full version of the Windows port of the game and it works great! Can still be found pretty cheap on eBay today considering all the great titles it contains: https://x.com/banditloaf/status/1669466388518 … 0BQjhmqZkJmyAjQ

Good spot!

Indeed, that's the Windows version - in 1995 they adapted all of the Wing Commander titles for Windows and released them on CD under "The Kilrathi Saga". There's also a PC Gamer release (which is really just the Wing Commander 1 Windows 95 version from KS) complete with frame limiter so that you don't have to attempt combat at 10,000 miles per hour. The tweet you linked is from Ben Lesnick, over at the Wing Commander CIC forum we consider him an encylopedia of Wing Commander knowledge, he later went on to work on Star Citizen. Anyway, he was able to pull some strings to get permission for the the aforementioned Wing Commander fan site to distribute the Windows Wing Commander 1 version publically.

asdf53 wrote on 2024-03-19, 19:53:

Dan386DX wrote on 2024-03-19, 18:25:

Interesting, thank you; I did read about that last night - some seem to have had great results, and 5MHz from a P75 is outstanding! Others have reported audio issues and choppiness, so I guess mileage will vary.

I did not have these problems on my Pentium 1 system, but I decided to test it just now on my "fast" system (Athlon 500). And indeed, the lowest setting (6.25%) did not work properly. The DOS prompt kept freezing and I got sprite flickering in one game (Commander Keen). Sound was fine. All problems disappeared with the next setting (12.5%). If you try it on your system please post your findings here.

Excellent, thank you - looks like I have a lot to consider here. I'll certainly give that a try with the VIA C3 and post my findings in this thread once I've tested a few apps and titles! Really appreciate all the help.