My Optiplex BIOS doesn't have an option for turning off the cache, so I think that this "Compatibility" mode is the same thing. I'm curious whether a faster GX1 with a PIII would run the Compatibility mode at the same speed, or if it would be faster, more like a 386. My guess is the latter, but some verification would be great.

I just played some Blood at 800x600 using the onboard ATI Rage Pro graphics, so VESA seems to be good right out of the box.

I was going to ask about the PSU... thought it's just the size/form factor that's different, but not the pins.. oh well.

Hmm maybe you'll want to try the obligatory WC2 speed test 😁, and how about SpeedSys? I recall a P3 450 Katmai with disabled caches to be around this range also (between 286 and 386), so maybe you'll have to go with much higher clockspeed for that.

Mau1wurf1977 wrote:

I found that a typical Slot 1 system with Cache disabled performs on the level of a 386SX. The higher the FSB, faster the memory, tighter the timings, higher the CPU clock (e.g. 1.4 GHz Tualatin) this improves somewhat.

I found that even playing old games like Indiana Jones and The Last Crusade is pushing your patience on a Cache disabled Slot 1 machine. The loading times are quite slow and it wasn't much fun.

That's the dilemma isn't it, the original experience vs speed!
Was that with RAMdisk though?

An update after a couple of months. I had purchased an OEM PIII-650 that came only with a flimsy heat sink (I started another thread about it), but I needed to find a fan (and a better heatsink) to get it to work. I decided to cut my losses and just buy a retail box PIII, which arrived today. It is a 700MHz Coppermine, comes with a nice attached sink and fan, and it works great with the GX1 after a BIOS flash.

But the interesting news is that the on-the-fly "Turbo" key combo is indeed relative to the CPU speed, according to Topbench. The old score in Compatibility mode (PII-333) was 38, equivalent to a 286-16. The PIII-700 returns a score of 61, which makes it equivalent to a 386-33. Loading SoftMPU brings it down to 48, which makes it work with even older DOS games.

So, if you're space-limited and don't mind PCI graphics (I'm using a GeForce FX 5500 PCI), an old GX1 with a CPU upgrade is an intriguing solution.

archsan wrote:

That's the dilemma isn't it, the original experience vs speed!
Was that with RAMdisk though?

No ramdisk, the usual CF cards. I don't think it's a storage problem, just not enough processing power to transition from room to room faster.

Mau1wurf1977 wrote:

Define "DOS Games" 😀

For early DOS games I would rather go with a Pentium.

I would do the same.. I have experienced in the past that mostly a pentium II is some what to fast to play dosgames on. But if you want to use a pentium II instead.
I wont recommend to go faster as a pentium II 233 mhz.

I have a Dual P2 400mhz server board someone gave me a few years ago and obviously DOS and Win9x won't see two processors but the nice thing is I can have 1GB SDRAM in it, tweak the win98se settings so it's stable and play the FPS titles like Build Engine and iD games well on it.

Like stated before, there are some early titles you'll run into problems with and I even have some problems with some demos running too fast. The dual boards are really nice because I have a triple boot with Windows XP SP3 and can boot into that and take advantage of the dual processors. It's fast enough to do some basic web surfing and I have a regular dual core laptop that I VNC into it for when I need that speed. You can use an older version of TightVNC for use in Win98 and use low colour mode and be able to really do it all.

I have some older Socket 7 boards and they have turbo functions which work great for those really stubborn titles. They even work great for demos that run too fast on the P2 and will avoid the Turbo Pascal bug as long as its under 200mhz.

Sometimes you can get away with using MoSlo, but I've never had too much luck with this utility. If the game works I've noticed it can have slowdowns if a lot of action is happening on screen and the music and sound will slow down at the same time and it really just breaks the overall flow for me.

boxpressed wrote:

In order to keep this hobby from getting out of hand, I want to build only two rigs, a fast Win98SE rig and a DOS rig. Ideally, […]
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In order to keep this hobby from getting out of hand, I want to build only two rigs, a fast Win98SE rig and a DOS rig. Ideally, I would like to have a 486DX2/66 powering my DOS rig, but I'm still sourcing the parts for it.

Yesterday, I picked up a Dell Optiplex GX1 from a local surplus sale. There was a sign on it that said it was not working and was for parts only. Another buyer was surprised I was buying it because it had been sitting there for a long time, apparently, surviving multiple biweekly surplus sales. It cost $0.50.

It turned out that the hard drive was fried, but I was able to get it up and running with a spare. It has a Slot 1 Pentium II-333. I did some research into this model, and it turns out that I have the earlier motherboard revision that does not allow for upgrading the processor to PIIIs. Although the onboard graphics are AGP (Rage Pro Turbo), there three PCI slots and three ISA slots (one shared). Now that I've brought this beast back to life, I'd kind of like to keep it. I like its looks and build quality, even though it uses a Dell proprietary form factor. I like having three ISA slots.

Would this be too fast to run games from the early 90s through 96 or so? I know that some of the Epic Megagames have speed problems. I'd really want it just to play those games that have native Ultrasound support.

It depends the game.

When I have bought my 386 in 1990, some games that worked very well on my 8086, were too fast with a 386. For exemple: crazy cars 2.
A cpu that allow to function all dos game natively without problem doesn't exist.
With a p2, some early dos games (cga/ega game released before 1990) can not function or function too fast.

The last game that I find too fast upgrading the cpu was conquest earth released in 1997.

A this time, some software to slow the cpu existed. Today, I think it's the same. See here http://www.cpukiller.com/

MoSlo works under dos, but either way these programs don't work very well for keeping a consistent slowdown. I noticed it will allow the games to run but if they are slightly demanding and have some decent action on the screen everything just comes to a crawl either way. This includes experimenting with running at 2%, 10%, 40%, etc, etc. If you're that concerned about it... get a list of games you want to play and find out what computers you need. It sucks, but if you want the proper compatibility you'll need more than one machine.

I think Moslo and the like just hog the timer interrupt, you're never going to get a consistent slowdown with that. On P2 and P3 platforms you can use FDAPM or Trottle, which actually throttle the CPU speed through ACPI with much better results.

Thanks for the suggestion. Throttle works great with my P2 Chipset.