The Leadtek WinFast 3D S320 II is a discontinued 1999-era AGP graphics-card family built around NVIDIA’s RIVA TNT2. It was not one universally identical card: Leadtek sold 16 MB and 32 MB versions, with “Pro” models adding digital LCD-panel output. Memory type, clock speeds, connectors, BIOS revisions, and even board layouts can differ, so the exact card matters.
Today, the S320 II makes sense for an authentic Windows 95/98 gaming PC, a period-correct Leadtek collection, or research into early AGP 3D hardware. It is not a practical modern graphics upgrade, and old listings should not be treated as evidence of current availability or pricing.
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What is the WinFast 3D S320 II?
“WinFast” was Leadtek’s graphics-card brand, while “3D S320 II” identified a board family using NVIDIA’s RIVA TNT2 GPU. The card should not be confused with the earlier WinFast 3D S320, which used the original RIVA TNT, or with related Leadtek products such as the S320 II Ultra, S325, TNT2 Pro, or TNT2 M64.
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Hardware databases identify the S320 II as RIVATNT2, confirming that it uses the standard TNT2 rather than a later TNT2 M64 or another similarly named chip. The Linux Hardware HOWTO and Illumos hardware-identification documentation are useful historical references for that distinction.
S320 II variants compared
| Model | Memory | TV output | Digital LCD output | Identification notes |
|---|---|---|---|---|
| S320 II-16 | 16 MB | Documented versions have S-Video and composite | No | Standard 16 MB configuration |
| S320 II-16Pro | 16 MB | Yes on documented versions | Yes | “Pro” primarily identifies the digital-panel connector |
| S320 II-32 | 32 MB | Documented versions have TV output | No | Standard 32 MB configuration |
| S320 II-32Pro | 32 MB | Yes on documented versions | Yes | 32 MB plus digital-panel output |
The table describes the principal four-model lineup, not every regional or cost-reduced board. Preservation documentation records examples using both SDRAM and SGRAM, as well as boards with different combinations of TV and digital-output connectors. Capacity alone therefore does not identify a card. DOS Days’ RIVA TNT2 reference is particularly useful for comparing physical variations.
What did “Pro” mean?
Within the standard S320 II lineup, “Pro” primarily indicated the presence of a digital output intended for DDWG-compatible LCD panels. It should not automatically be read as “TNT2 Pro” or as proof of a faster GPU. Later NVIDIA products used “Pro” as a performance designation, which is why this name is easy to misinterpret.
Specifications and features
| Specification | What the evidence supports |
|---|---|
| GPU | NVIDIA RIVA TNT2 |
| Bus | AGP 4x/2x/1x listed for the family |
| Memory | 16 MB or 32 MB, depending on the board |
| Memory technology | Both SDRAM and SGRAM examples exist |
| Core clock | Around 140 MHz on standard examples |
| Memory clock | Published figures include roughly 150–165 MHz, depending on board and memory |
| Video outputs | S-Video and composite on documented TV-output versions |
| Digital output | Available on applicable Pro versions |
| Cooling | Heatsink-and-fan cooling on documented examples |
Clock figures are not universal specifications for every surviving S320 II. AnandTech described a standard core around 140 MHz and a 16Pro memory specification of approximately 150 MHz, while other period listings give different memory figures. The installed memory chips, BIOS, and board revision are more reliable clues than a generic internet specification table.
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The TNT2’s feature set was advanced for its period. The card provided hardware triangle setup, Direct3D acceleration, DirectX 6-era support, 32-bit ARGB rendering, a 24-bit Z-buffer, an 8-bit stencil buffer, perspective-correct texture mapping, anisotropic filtering, and 128-bit 2D and DirectDraw acceleration. It also included YUV conversion and period MPEG-1/MPEG-2 and DirectShow video-acceleration features. These capabilities describe late-1990s software, not modern video or graphics support. The contemporary Leadtek review lists the family’s feature set and display capabilities.
Performance in its historical context
The S320 II was a strong late-1990s Direct3D accelerator, particularly for period games running under Windows 95 or Windows 98. Its advantage was most meaningful at the resolutions, APIs, CPUs, and drivers of that era. It supported 32-bit rendering and TNT2-generation texture and filtering features, but its performance should not be summarized with one timeless benchmark score.
AnandTech’s reviewed 16Pro sample used a roughly 140 MHz core and was positioned against standard TNT2 implementations commonly running around 125 MHz. That higher clock gave Leadtek a useful advantage over some competing cards. The review’s results apply to that specific sample and configuration, not automatically to every 16 MB or 32 MB S320 II.
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HotHardware tested a 32 MB SGRAM model in a Pentium II system running Windows 98, DirectX 6.1, and NVIDIA TNT Detonator drivers. Its review praised the card’s image quality and design, but those results cannot be transferred directly to a 16 MB SDRAM board or to an Ultra model. The HotHardware review identifies its test sample and platform.
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Period comparisons included standard TNT2 cards, higher-clocked TNT2 Ultra boards, 3dfx Voodoo3, earlier TNT and Voodoo2 hardware, and Guillemot’s Xentor 32. Hardware.fr’s historical comparison found the standard 16 MB S320 II more defensible than the more expensive 32 MB Ultra offering, but that was a 1999 value judgment based on period prices—not a current buying recommendation. Hardware.fr’s comparison also demonstrates why clocks and exact variants matter.
Overclocking: interesting history, poor restoration policy
Some S320 II samples overclocked well, but historical results are not guaranteed operating ranges for cards now more than two decades old.
- AnandTech’s Samsung-memory 16 MB sample reached approximately 170 MHz memory in testing from a stated 150 MHz specification.
- Hardware.fr reported a tested standard S320 II reaching a 160 MHz core, while Hyundai 7 ns memory produced graphical errors above approximately 170 MHz.
- The same comparison found the S320 II Ultra less impressive than some faster-clocked competitors and unstable beyond particular tested limits.
Those results belong to individual 1999 samples with specific memory chips, cooling, BIOS versions, and test conditions. A surviving board may have a degraded fan, aging capacitors, oxidized contacts, or damaged memory. For a collectible card, preserving the original hardware is usually more valuable than extracting a small clock-speed increase.
Drivers and operating systems
Period driver listings identify Leadtek S320II packages for Windows 95, Windows 98, Windows NT 4.0, and Windows 2000. A contemporaneous announcement also separated the standard S320II driver directory from the S320II Ultra directory. Do not assume that similarly named packages or BIOS files are interchangeable. The period driver announcement records that distinction.
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- Photograph the board and identify its exact model.
- Record the BIOS string if the machine still boots.
- Use a period-correct NVIDIA reference or Leadtek driver matched to Windows 9x, NT 4.0, or Windows 2000.
- Keep a known-good PCI VGA card available for troubleshooting or recovery.
- Do not use files intended for the S320 II Ultra, TNT2 Pro, TNT2 M64, or another manufacturer’s board.
The available evidence concerns period operating systems. It does not establish official modern Windows 10 or Windows 11 support. Expecting contemporary driver support, modern hardware-accelerated video playback, or current display connectivity from this card is unrealistic.
AGP compatibility and BIOS troubleshooting
The TNT2 family specification lists AGP 4x/2x/1x operation, but that does not guarantee compatibility with every motherboard. AGP slots and cards can differ electrically, and later systems may be particularly troublesome. Verify the motherboard’s AGP voltage and compatibility rather than relying only on the physical shape of the slot.
If the system shows a blank screen or becomes unstable
- Power down and reseat the card, then clean the contacts carefully if oxidation is visible.
- Test basic VGA output before installing drivers.
- Return the motherboard to conservative AGP settings and disable aggressive options while diagnosing.
- Check that the fan starts reliably and that the heatsink is firmly attached.
- Try a period driver appropriate to the operating system.
- Compare the BIOS string with the exact board model and revision.
A period AnandTech forum report describes an S320 II system that became stable after the user flashed a newer European Leadtek BIOS. This is evidence that BIOS and motherboard-compatibility problems occurred, but it is anecdotal and does not establish a universal fix. The forum report should be treated as historical troubleshooting evidence, not as a general flashing instruction.
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Never cross-flash a standard S320 II with an Ultra, TNT2 Pro, or another manufacturer’s BIOS. Before any flash, confirm the exact model, PCB revision, memory configuration, and regional image. Keep a PCI fallback card or a known recovery method available because a wrong image can leave the board unusable.
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How to identify a particular S320 II
Ask for clear front and rear photographs when buying one. Record:
- PCB markings and revision numbers.
- Leadtek model stickers, labels, and barcodes.
- Memory-chip manufacturers and part numbers.
- The number and physical arrangement of memory chips.
- The BIOS chip and visible BIOS text.
- Whether cooling uses a fan or a passive heatsink.
- Presence of S-Video and composite connectors.
- Presence of the digital LCD-panel connector.
- Any markings for 16 MB, 32 MB, Pro, or Ultra.
Do not infer the variant from the seller’s title alone. “S320 II” may be used loosely for a 16 MB card, a 32 MB card, a Pro model, an Ultra model, or a visually similar TNT2 board. Memory type and output connectors are board-level specifications, not guarantees shared by the entire family.
Cooling and restoration
Documented S320 II boards commonly used active cooling. Before extended testing, confirm that the fan starts immediately, does not rattle, and continues running. A silent fan may be healthy, but it may also be seized.
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- Replace a seized or intermittent fan before benchmarking.
- Inspect the PCB for leaking capacitors, corrosion, and damaged components.
- Check 2D output, 3D acceleration, TV output, and memory stability separately.
- Preserve the original cooler for historical completeness, but use a safe replacement for regular operation if necessary.
AnandTech found the documented fan-and-heatsink arrangement effective and discussed replacing the original thermal interface with thermal grease. That is maintenance guidance for a particular period board, not a reason to assume every surviving cooler remains safe.
Should you buy one today?
Good reasons
- You are building an authentic 1999-era Windows 95/98 gaming machine.
- You collect Leadtek or early TNT2 hardware.
- You want to study the transition to AGP and DirectX 6-era 3D acceleration.
- You specifically need period TV output or a compatible digital-panel connection.
Reasons to avoid it
- You need modern gaming performance.
- You require current Windows driver support.
- You want HDMI, DisplayPort, widescreen support, or modern digital-display compatibility.
- You need dependable everyday workstation graphics.
- You are seeking maximum performance per dollar.
For a retro build, the 16 MB standard card is often the simplest and most representative choice. Choose a 16Pro or 32Pro when the verified digital output is important. A 32 MB card may be desirable for collection completeness, but capacity alone does not prove higher performance. Treat the Ultra as a related but distinct product rather than an ordinary S320 II configuration.
There is no responsible universal 2026 price for this family. Value depends on the exact variant, originality, box and documentation, fan condition, tested status, and provenance. A seller who cannot show the connectors, memory chips, PCB, and BIOS information is offering substantially less certainty than the model name suggests.
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