Introduction

This is a test I wanted to do for myself for a pretty long time. Without any testing, my answer on how fast a CPU should be so that a Banshee isn't held back would have been "400-500 MHz depending on the card".

To finally answer this question thoroughly, I equipped my Slot1 testmachine with seven different Slot1 Pentium II/III CPUs and picked nine Banshees from my collection which represent all combinations of core/mem clocks for SDR- and SGR- Banshee models that I am aware of. This should give us an excellent impression, how far these cards scale and how much of an impact on scaling the core/mem clocks and the memory type installed on the cards have.

The Test System

The testsystem is the following:

For the OS, I used Windows 98 Second Edition with DirectX 8.1 as well as an inofficial Service Pack installed. For each card, I restored a pre-configured system-image before testing.

The Benchmarks

All benchmarks were made using the latest official 3dfx Banshee driver (1.04.00) for Win9x with the following driver settings (identical for D3D and OpenGL / Glide):

• VSync: off
• Filter: 4x1 (linear)
• LOD: +1
• Alpha-blending: sharper

These settings were applied via VControl and are my overall recommendation for daily use. The benchmark suite includes 3DMark99 for the D3D API, Unreal Tournament for 3dfx Glide, as well as Quake 2 and Quake 3 Arena, representing an early and a more modern OpenGL title. For both of the OpenGL games, the 3dfx MiniGL driver 1.49 was used.

All benchmarks were run in the 800x600 resolution. In my personal opinion, this is the best resolution to run games on a Banshee card. Performance is always usable in period-correct games and furthermore, you get integer-correct scaling, if you are using an older 21" TFT with a 1600x1200 native resolution. For those who don't have enough room for a CRT display, these can be great alternatives for retro-gaming.

The first thing that becomes obvious, is, that 3DMark99 MAX requires at least a 550 / 600 MHz CPU for a fast second-gen 3D accelerator. Even the slowest Banshee (which is the Miro HiScore Pro, representing all SD-RAM equipped models which clock at 100 / 100 MHz) shows a linear scaling all the way up to the 550 MHz Coppermine CPU.

The fastest Banshees (GA-630 and Monster Fusion) show a notable jump in the 3DMark score coming from the 450 MHz Pentium II. These two cards even scale up to 700 MHz in this test, performance for most other cards remains largely unchanged beyond 550 MHz. Some cards like the Vulcan B with its fast 115 MHz SGR memory gain a few points with faster CPUs, but that's no such thing as scaling.

The DCS card with SDR memory and 105 / 105 clocks performs about identical as SGR cards clocking at 100 / 100 MHz, such as the two Asus Banshees.

8 MB of memory seems to be no disadvantage in this test, both Asus cards achieve nearly identical scores.

Much as the 3DMark99 MAX, UT's benchmark.dem timedemo also suggests the Pentium III 550 MHz as the sweet spot for most cards. Even the GA-630 gains less than 1 FPS when replacing this CPU with a 850 MHz variant. The biggest scaling happens up to 450 MHz. All cards except the Diamond Monster Fusion and the Gigabyte GA-630 achieve less than 1 additional FPS, when replacing the Pentium II 450 MHz with a 550 MHz Coppermine.

Furthermore, this graph clearly shows that overclocking both the chip and the memory has a significant impact on performance. The trio, consisting of the Skywell model clocking at 100 / 110 MHz and the two DCS cards clocking at 105 / 105 MHz, perform about the same and are already about 2 FPS faster on average than all the cards clocking at 100 / 100 MHz.

Moreover, the Vulcan B with 100 MHz on the chip but memory clocking at 115 MHz is even faster than these cards, which indicates that already a stock-clocked chip can benefit from the increased memory bandwidth. As the fastest of the bunch, the Diamond and Gigabyte models demonstrate significantly greater performance than all the others due to their unrivalled clock rates.

The 8 MB Asus card, on the bottom of the graph, struggles in this game. Its average FPS shown in this graph do not tell the whole story - the biggest problem are the minimum FPS, which frequently dip down into the single digits. For cards with only 8 MB of memory, the details should be reduced to smooth out the performance.

In Quake 2, the CPU used doesn't matter for a Banshee card. Even the venerable 300 MHz Klamath is more then fast enough for even the fastest Banshee and doesn't take away much of its maximum performance.

8 MB of memory is suffient and memory bandwidth doesn't impact performance as much as increased clockspeed of the chip, as shown by the DCS cards which both have 5 MHz overclock on both chip and memory. The SDR model matches the performance of the Skywell card, which has +10 MHz on the (SGR) memory, the DCS card with SGR memory even matches the performance of the Vulcan B, which runs at a memory clockspeed of 115 MHz but has no "overclock" on the chip.

Quake 3 Arena shows a relatively similar scaling pattern as 3DMark99 MAX. Something that strikes the eye even more than in the aforementiond benchmark, is, that the 600 MHz Katmai performs worse than the 550 MHz Coppermine Pentium III. This serves as a reminder that architectural improvements can outweigh a slight advantage in clock-speed. The more advanced a 3D engine is, the more it benefits from a fast L2 cache. This is one of the reasons why both Intel and AMD replaced the external L2 cache designs of early Pentium III and Athlon processors with full-speed on-die L2 cache in the Coppermine and Thunderbird cores.

Other than that, Quake 3 shares its hunger for raw rendering power with its predecessor. For the Banshee chip this counts double, because it doesn't support multitexturing, which the game makes heavy use of.

The conclusion is straightforward: A small coppermine CPU is plenty enough for almost all Banshees. If you are after the last 1-2 FPS for your Gigabyte GA-630 or Diamond Monster Fusion, a 700 or 850 MHz Coppermine can help squeezing the last bit of performance out of these cards.