First post, by H-Atkinson

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I have a Thinkpad 701C, and was recently able to obtain the correct docking station adapter to use it with the Thinkpad Dock II (3546), which has, among many other expansion options, 2 full-length 16-bit ISA slots. I already know that ISA-based 3d accelerators non-existent save for a few CAD cards, but what I don't know is if there are any ISA cards out there faster than the Chips and Technologies CT-65545 VLB chip that the 701C already has on-board. Obviously 16-bit ISA with no VLB is pretty limiting, but would something like an ATI Graphics Ultra Pro ISA be any faster? I can't seem to find any benchmarks that meaningfully compare the 2.


Reply 1 of 2, by WJG6260

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I can’t say I have any experience with the Chips 65545, but I’ve extensively used a Chips 64300 VLB card. From what I’ve read, they seem to be similar; both are 32-bit cores and have 32-bit memory interfaces, but the 65545 appears to be a later generation card and clocked a smidgen higher. Speaking from my experience with the 64300, for whatever that’s worth, here’s the thing: this chipset is very much underrated in DOS. The Chips 64300 VLB cards match Tseng ET4000/W32Ps in DOS gaming, and in Windows, performance is in the upper echelon of 32-bit cards.

But—and this is the big catch—the Chips 64300 does not perform well in true color/24-bit modes. The Windows 95 driver is buggy and, while there’s apparently later drivers that can fix this, I have not tested them. That being said, I do not believe that would apply to the Chips 65545, as that’s a later generation chipset and built around the early Windows 95 era, as far as hardware goes.

I do have an ATI Graphics Ultra Pro in ISA. It is not faster than the Chips card. Not at all. It is a very competent ISA Windows accelerator and a very fast ISA card, but that’s the thing: it’s ISA. The bus clock is ~8MHz, compared to the 25-33-40MHz that the VLB card will be operating at, since VLB is a local bus. I just tested the two, and here’s some highlights:

Graphics Ultra Pro
3DBench 1.0C - 38.7 FPS
PC Player Mode 101 - 5.0 FPS
X-VESA Mode 101 - 3.9 MB/s
VidSpeed Mode 101 - 3.9MB/s 32-bit writes
Doom: ~21 FPS

Chips F64300
3DBench 1.0C - 49.2 FPS
PC Player Mode 101 - 5.3 FPS
X-VESA Mode 101 - 31 MB/s
VidSpeed Mode 101 - 30 MB/s 32-bit writes
Doom: ~29 FPS

Granted, this is on a 486DX2-66 with 32MB of RAM and an APC Predator I Plus Motherboard featuring the Symphony Haydn II chipset. There’s definitely limitations, but I’d expect the ISA card would not be able to catch up, even on a faster system.

Even the fastest of ISA cards—the Mach64 VRAM, Cirrus GD5434, Tseng ET4000/W32i, and S3 805i/928—are all somewhat limited in terms of what they can do. They’re all pretty darn fast in Windows, but not great in DOS, especially compared to later cards. Compared to other ISA cards? They’re very, very capable. The Mach32 with 2MB of RAM should be up there, close to these cards, but not quite there.

Compared to a VLB card? They’re being left in the dust. The only place that they can really keep up is Windows, and even then, VLB cards with competent drivers are usually the way to go.

This is just my two cents, but I hope this helps!

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"Never trust a computer you can't throw out a window." - Woz

Reply 2 of 2, by H-Atkinson

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Thanks for the insight. I probably will just go as-is with the Chips and Technologies for now since it seems like there isn't much room to improve without having PCI or ISA. If I see a good price on a Mach64 or Tseng ET4000 I'll still pick one up to compare (and of course share my results), but for now I'll just stick with the onboard chip.

As for Win95 performance, I'll do some testing and get back to you. Right now I'm running a partitioned drive with DOS/Win3.1 and OS/2 Warp 3. I have another drive I can put Win95 on and test with coming soon (701C use a caddy that's a pain to take apart, so its hard to just drop any old drive in, and for whatever reason you can't boot off of CF cards, even though it supports booting PCMCIA network cards).

My CPU is a 486DX5-75mhz right now, but I have an AM5x86-133mhz that I plan to swap in (waiting on more solderwick), so it potentially could yield even better results still.