Retro Review: Tseng Labs ET4000AX Part 2
8th November 2022
In part 1 we explored this SVGA card from 1991. In part 2, I will run some base benchmarks on the card. Here's the card in question again:
My original 16-bit ISA ET4000 card from 1992
Because this is an ISA card I want to be certain throughout my benchmark tests that I am properly evaluating the card's best performance, i.e. no other bottlenecks from the host PC. In order to achieve this, I have installed it into my mid-range retro PC with these specs (I did a full 3-part article on this retro PC build):
| Motherboard | Gigabyte GA-5AX Super 7 Rev 4.1, 512 KB L2 cache (1998) |
| CPU | Intel Pentium MMX 200 MHz (1997) |
| Memory | 32 MB PC133 SDRAM |
| Hard Disk | 512 MB CompactFlash card via CF-to-IDE adapter |
| Floppy Drive | Gotek floppy emulator w/ FlashFloppy |
The above system should ensure the card runs without impedance from the rest of the system, so my results ought to be the card's "absolute best". The Gigabyte GA-5AX has BIOS settings that allow me to adjust the AT Bus (ISA bus) clock from 7.16 MHz to CLK2/6, CLK2/5, CLK2/4, CLK2/3 to the fastest CLK2/2, so I will be checking the affect on this bus overclock as well.
A Note on VESA Compatibility
I will also try to test the VESA modes. In the late 1980s video card manufacturers were pushing beyond the boundaries of IBM's VGA standard which maxed out at 640 x 480 in 256 colours. These manufacturers rarely collaborated to agree on the way in which their cards would access these 'extended' graphics modes like 800x600 and 1024x768, which left software developers having to create separate drivers for each manufacturer and card. This of course was problematic. By around 1990, VESA (the Video Electronics Standards Agency) worked to standardise screen resolutions and colour depths and got buy-in from the major manufacturers to agree upon a set of video modes they would support in this standardised way.
The ET4000AX doesn't come with built-in VESA support in the BIOS- this was only really common in cards from around 1994 onwards - but if a card supported extended VESA modes, the card manufacturer would typically provide a VESA driver on its utilities and drivers disk. These VESA modes were often referred to as VESA VBE, or "Video BIOS Extensions", since that's what they did - extend the card's video BIOS to include function calls that software could use to make use of these VESA graphics modes. A VESA (or VBE) driver, at least in DOS, was a TSR (Terminate and Stay Resident) utility that sat in memory and trapped calls to the video BIOS and converted them to be VESA-compliant so that the software would be able to work. <- Is this accurate, or did the utility simply put new BIOS functions into memory that could be called to talk to the graphics card at a given address? Let me know if you know!
I don't have the disk for my ViewTOP card specifically, but Tseng Labs had generic drivers and utilities that would usually work with all ET4000-based cards. The one provided by Tseng Labs is called TLIVESA.EXE. Another very common one that worked across multiple cards was UNIVESA, later renamed UNIVBE.
For synthetic benchmark testing, I am using these utilities:
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With the machine set to the fastest setting (caches-wise and the AT bus set to CLK2/4), I installed UNIVBE v4.0, which provides us with VESA 1.2 compatibility:
Here were the results:
Starting with the AT (ISA) bus to set to its default of 7.16 MHz gave these results:
Overclocking the ISA Bus
I mentioned the fact my motherboard can allow me to set the clock speed the ISA bus runs at. The options are 7.16 MHz, CLK2/4, CLK2/3 and CLK2/2. The CLK2 here refers to the speed of the PCI bus, which is 33.3 MHz, so for example a setting of CLK2/4 is 33.3 divided by 4, or 8.325 MHz.
Changing the AT (ISA) bus to CLK2/4, gave these results:
Changing the AT (ISA) bus to CLK2/3, gave these results:
Changing the AT (ISA) bus to the fastest setting of CLK2/2, gave these results:
Here's a summary of those stats:
| AT Clock | 3DBench 1.0 | 3DBench 1.0c | Chris Bench (low) | Chris Bench (high) | PCP 320 | PCP 640 | Doom (low) | Doom (high) | Wolf3D |
|---|---|---|---|---|---|---|---|---|---|
| 7.16 MHz | 28.5 | 27.9 | 21.7 | 5.8 | 19.3 | 4.8 | 82 | 12 | 23.7 |
| CLK2/4 (8.25 MHz) | 31.2 | 30.5 | 27.2 | 7.6 | 19.7 | 5.0 | 91 | 14 | 27.1 |
| CLK2/3 (11 MHz) | 37.0 | 35.8 | 27.2 | 7.6 | 22.8 | 5.9 | 104 | 16 | 32.2 |
| CLK2/2 (16 MHz) | 43.4 | 42.0 | 33.6 | 9.0 | 26.3 | 7.1 | 119 | 19 | 37.2 |
So on average we see a 50% improvement in our graphics performance by overclocking the ISA bus to the maximum of CLK2/2. Of course, not all motherboards (especially earlier ones) have this capability, but if it's there and you are using an ISA graphics card it's well worth giving it a try. I've overclocked this ET4000 before so I know it's very stable. I had a much worse time overclocking my Trident TVGA8900 cards, where anything over the 8 MHz mark would cause the system to hang or video artifacts to appear.
While this speed improvement looks good on paper, in real-world tests such as DOS gaming it is worth noting that software, including games, simply didn't require overclocking like they did later on, and just about any VGA card would perform adequately. However, if running Windows you would certainly notice the difference, especially at higher resolutions like 800 x 600 or 1024 x 768.
** UPDATE - More comparisons ** In March 2025, I was testing some VRAM-based ISA graphics accelerator cards, and included the ET4000 card here in those test. They were run on a much faster machine (Pentium III 750 MHz) to avoid any other bottlenecks, on a motherboard that did not allow for any ISA bus speed adjustments, so assume it's running at around 8.5 MHz. Here were my findings:
| Diamond Stealth VRAM 80ns (1992) | ATI VGA Wonder GT 100ns (1993) | Tseng Labs ET4000 1 MB 80ns (1992) | Trident 8900CL 1MB 70ns (1992) | |
|---|---|---|---|---|
| Doom timedemo | 25.6 fps | 34.3 fps | 37.2 fps | 44.5 fps |
| Superscape VGA Benchmark 1.0 | 32.2 | 71.4 | 71.4 | 90.9 |
| Superscape VGA Benchmark 1.0c | 31.9 | 67.7 | 69.3 | 83.6 |
| Chris' 3D Bench | 34.2 (20.5 fps) | 89.0 (53.4 fps) | 92.5 (55.5 fps) | 117.5 (70.5 fps) |
| Chris' 3D Bench SVGA | 7.5 (4.5 fps) | (VESA not found)* | 23.1 (13.9 fps) | 27.9 (16.7 fps)** |
| PC Player 320x200 x 8 bpp | 22.7 | 53.0 | 54.8 | 66.5 |
| PC Player 640x480 x 8 bpp | 3.7** | (VESA not found)* | (VESA not found)* | 15.7 |
| Vidspeed | 65,024 bytes/ms normal RAM 3121 - 3324 (text) 1602 - 1756 (CGA) 1601 - 1757 (EGA) 1592 - 1602 (VGA) 1322 - 1322 (SVGA) |
65,024 bytes/ms normal RAM 3543 - 3555 (text) 2613 - 3527 (CGA) 2608 - 2619 (EGA) 2614 - 3509 (VGA) 1730 - 3593 (SVGA) |
65,024 bytes/ms normal RAM 4561 - 4571 (text) 4545 - 4555 (CGA) 3580 - 3580 (EGA) 3579 - 3605 (VGA) 3579 - 3605 (SVGA) |
65,024 bytes/ms normal RAM 4394 - 4413 (text) 4199 - 4391 (CGA) 4201 - 4320 (EGA) 4082 - 4388 (VGA) 4082 - 4389 (SVGA) |
| Dr.Hard Video Performance | 786,239 cps (direct text 8-bit) 1,550,639 cps (direct text 16-bit) 263,972 cps (write via BIOS) 18,199 cps (write via DOS) 146,247 pixels/s (write via BIOS) 1.55 MB/s text 8-bit 3.09 MB/s text 16-bit 3.15 MB/s text 32-bit 1.57 MB/s graphics 8-bit 1.65 MB/s graphics 16-bit 1.65 MB/s graphics 32-bit 3.1 MB/s max video transfer rate |
920,919 cps (direct text 8-bit) 1,761,759 cps (direct text 16-bit) 358,903 cps (write via BIOS) 18,199 cps (write via DOS) 260,399 pixels/s (write via BIOS) 1.81 MB/s text 8-bit 3.55 MB/s text 16-bit 4.38 MB/s text 32-bit 1.80 MB/s graphics 8-bit 3.51 MB/s graphics 16-bit 4.30 MB/s graphics 32-bit 4.3 MB/s max video transfer rate |
22,578,919 cps (direct text 8-bit) 46,905,039 cps (direct text 16-bit) 438,401 cps (write via BIOS) 25,479 cps (write via DOS) 254,771 pixels/s (write via BIOS) 4.57 MB/s text 8-bit 4.56 MB/s text 16-bit 4.57 MB/s text 32-bit 1.84 MB/s graphics 8-bit 3.58 MB/s graphics 16-bit 4.51 MB/s graphics 32-bit 4.5 MB/s max video transfer rate |
1,146,599 cps (direct text 8-bit) 2,191,279 cps (direct text 16-bit) 352,206 cps (write via BIOS) 21,839 cps (write via DOS) 265,031 pixels/s (write via BIOS) 2.26 MB/s text 8-bit 4.38 MB/s text 16-bit 5.84 MB/s text 32-bit 2.25 MB/s graphics 8-bit 4.40 MB/s graphics 16-bit 5.84 MB/s graphics 32-bit 5.8 MB/s max video transfer rate |
| MonTest v1.93.0B Video Card Performance | 8,387 chars/ms (hard) 900 chars/ms (BIOS) |
10,163 chars/ms (hard) 1,577 chars/ms (BIOS) |
27,261 chars/ms (hard) 1,257 chars/ms (BIOS) |
12,744 chars/ms (hard) 1,046 chars/ms (BIOS) |
Games Testing
In Part 3 I will switch my focus to testing this card out on some games, including Indianapolis 500: The Simulation, The Cycles: International Grand Prix Racing, F-15 Strike Eagle II, Ferrari Formula One, Their Finest Hour: Battle of Britain, and more. For comparison, I will run the same tests on cards that were competing with the Tseng Labs one around the same time period.