Hi!

I also use mico drivers every now and then. But mostly Seagate and I believe one Hitachi. But shouldn't make a difference. A slow hard drive does not cause slow downs in games.

The benchmarks scores are fine and the graphics card is also a very good performer in DOS games.

You can run the benchmarks here (one download in ZIP) and compare it with other DX2 and DX4 machines in the database:

Phil's Ultimate VGA Benchmark Database Project

Because "slowdowns" are subjective, personally I can see some slowdowns on a Pentium 100 when the action gets intense, but they are super minor. A DX4 should play it fairly well however.

I would see if you could tighten your cache and memory timings and stay stable. It will make the system a lot faster if you can.

Your VGA also appears a little slow

Apparently you can't really trust speedsys for video scores.

Your hardware setup looks more then enough to play Doom. I'm assuming your playing in pure dos
Have you got a old HDD to test with? then you'll know one way or the other if its the CF card, shouldn't think so though

Love that case btw!

When I had the Am486DX4-100 installed in a VLB motherboard I measured this:
Doom Registered v1.9 "-Timedemo Demo3"; 1 level of green border; with sound+music: 39,71 Frames per second.
The frame rate cap of the game is 35 FPS.
Frame rate is Calculated like this: FPS = Gametics / Realtics x 35

If the disk drive is the cause of slowdowns, then it should only slow down when new data is loaded. Not when just running circles in the same room.

The game stops when something explode or a new bad guy show up... the same thins happens in duke nukem 3d 🙁

I'm pretty sure it's a microdrive problem, I put the microdrive in a 486 DX2 66 MHz I have and where I'm pretty sure DOOM run fine and the same thing happened...
I will try to find a new CF card to try.

You should start by comparing your Speedsys scores with those found in spreadsheet contained within the Ultimate 486 Benchmark Comparison pdf document.

For an AMD DX4-100 with 8 KB of write-through L1 cache, as you have, you should be targeting Speedsys numbers in this [stable] range,

L1: 73 MB/s
L2: 51 MB/s
RAM: 37 MB/s.

Your scores are nearly half of these in cases and I would expect your Doom framerates to reflect this. With most motherboards, these slow speeds can be corrected by adjusting the external cache and memory timings within the BIOS.

My speedsys scores with that CPU are:
L1: 62,91MB/s
L2: 40,53 MB/s
RAM: 27,12 MB/s (60ns FPM, minimal waitstates)
Image in this topic
Which is similar to b_rros, except for the RAM speed.
Lower then what feipoa got, by 10MB/s each!? But I did not have a problem with Doom, and was in the impression that this is typical performance.

Then, I have bad experience with 2.5" laptop mechanical drives causing sound prefetch stutters in games. Solid state media has thus far been sufficiently fast to avoid such annoyance.

I have found that SiS 496/497 and UMC 8881/8886 PCI-based motherboards tend to yield the numbers I noted with optimal stable timings. SiS 496/497 might yield 1-2 MB/s faster for the memory test. I, unfortunately, do not have any data for non-PCI 486 motherboards.

Regardless look at my speeds: download/file.php?id=14313

Your memory speed at 18MHz is quite dismal for a 496 chipset board

Ok, I was allways a guy of "LOAD SETUP DEFAULTS" in BIOS and go with it 😀

It's perfectly understandable if you just say something like RTFM, but... any chance of helping me tweaking the BIOS settings?
Here's how my BIOS is right now...

What exactly do I need to change?

And about the manual, I found one online, it's here if anyone wants it:

https://dl.dropboxusercontent.com/u/912999/30h-mu20.pdf

I have a Am5x86 P75 133 MHz processor, if I try to boot the motherboard with it it's detected as a 486DX4-s processor but at 100 MHz, in the manual I can't find this processor listed. Can I use it using another processor settings?

Thanks a lot again for all your help

OK, I found an old 800MB hard drive, move some cards and cables around, and install it in the PC and... DOOM runs fine now, I even installed Duke Nukem 3D (1.3 version) and the UNIVBE driver that came with the CD and I can even play Duke in 320x400 with no slow downs.

Maybe my microdrive is bad, I never used it much. I will still use it as a secondary drive on this PC to transfer things around.

Anyhow, I would still like to tweak the BIOS settings and install the Am5x86 processor if possible, so any help will be apreciated. 😀

Cool, always nice when you figure something out.

This link explains what the BIOS setting mean in plain English, so you can fine tune your PC and know what your doing at the same time 😀
http://www.pcguide.com/ref/mbsys/bios/set/index.htm

chinny22 wrote:

This link explains what the BIOS setting mean in plain English, so you can fine tune your PC and know what your doing at the same time 😀
http://www.pcguide.com/ref/mbsys/bios/set/index.htm

Thanks 😀

philscomputerlab wrote:

Cool, always nice when you figure something out.

I updated the spreadsheet with my results, at line 469. For what I could see it's not that much different from others with DX4 machines 😀