I think it's the audio channels getting mixed that takes CPU time. Try configuring it with less voices / channels to see if it speeds things up?

SRQ wrote:

Is this just par for the course for these later cards, or am I missing something? This is with EMM386 off and no TSRs running.

I agree with Phil - Say, what happens without EMM386 loaded ? You've got a new VLB card, so I assume it's a 486 rig, right ?
Early 486 processors may get slowed down a little bit by V86 (UMBPCI might work if it is a VIP board; QEMM and URAM+HiRAM, etc. are also alternatives).

Jo22 wrote:

SRQ wrote:

Is this just par for the course for these later cards, or am I missing something? This is with EMM386 off and no TSRs running.

I agree with Phil - Say, what happens without EMM386 loaded ? You've got a new VLB card, so I assume it's a 486 rig, right ?
Early 486 processors may get slowed down a little bit by V86 (UMBPCI might work if it is a VIP board; QEMM and URAM+HiRAM, etc. are also alternatives).

All testing was done without any memory manager, or anything running at all- hitting F8 and pressing N a whole bunch :p The part of my post you quoted actually says that...
All testing was done with 8 voices- Aztech and SB16. Is the SB16 doing 8 /stereo/ voices and doubling the amount of processing needed?

SRQ wrote:

All testing was done without any memory manager, or anything running at all- hitting F8 and pressing N a whole bunch :p The part of my post you quoted actually says that...
All testing was done with 8 voices- Aztech and SB16. Is the SB16 doing 8 /stereo/ voices and doubling the amount of processing needed?

Sorry, missed the "off" part.. 😅 I'm reading this on a 15" screen right now and have to zoom out, so I can see the thread in a whole.
The slowdown then might be related to how the sound blasters work, dunno.
Maybe the Aztech is more efficient in native mode then (in case the game you ran did make use of it).

Any improvement if you OC the ISA bus?
If it's a DX2-66 or DX4-100 (3x33), then the next step down on the ISA divider takes it from 8.25MHz to 11MHz - most cards can deal with that.
If it's at 40 base, then the next step takes ISA from 8MHz (/5) to 10MHz (/4)

Hooow would I do that? I don't see any BIOS options or jumpers for it.
It's a 66.

The ISA clock divider is usually available in BIOS, it's possible that it may be hidden and set automatically, but I seem to recall it being available on everything I remember. For AMI BIOS, under advanced chipset setup

One other thing comes to mind, does Doom use DOS/4GW? - it might be more efficient with DOS/32A which can apparently work as a drop-in replacement for DOS/4GW - If it is, you'll probably see the DOS/4GW version banner at the start.

It does but it's baked into the executable itself.
Say, are there any good DOS ports that might speed it up? I thought they were all Pentium-focused but I suppose I should ask.

Oh it's only a 66? Not sure what you expected.

Yea that isn't going to cut it I'm afraid. You can reduce the details and make the window smaller to get better FPS.

Well, I suppose that makes sense. Damn, wasn't a DX2-66 top-end when Doom was released?
I must just be spoiled for new games running well on maxed settings these days on new hardware.

A good score for a DX2/66 on Doom timedemo is about 25 fps (74690 gameticks / ~3000 realticks). That's a good benchmark to compare to. Just run from Phil's DOS benchmark kit, it's already preconfigured and easy to run. I managed 27 fps on mine with tweaked BIOS timings and a Cirrus Logic GD5424 VLB.

Yeah a 133MHz 486 can do DOOM properly, just, but I stick to a Pentium.

SB16 would also be capable of higher sample rates, but if I remember correctly, it doesn't matter anyway because Doom is hard coded to initialize its sound system at 11KHz. Which is amusing, since there are a handful of 22KHz sound effects in Doom 2. Namely, the reloading sound effects of the Super Shotgun. Doom 95 was hard coded to assume all sound effects were the same sample rate as the mixer, so there was no pitch variation, and the Super Shotgun was slowed down to half speed.

SRQ wrote:

hitting F8 and pressing N a whole bunch :p

You can hit F5 instead.