NVIDIA RIVA TNT2 M64

In the last few days, we’ve taken a look at two of the newest members in NVIDIA’s lineup – the GeForce 256 and the TNT2 Pro. But we haven’t forgotten that there’s a huge market out there for a price and performance leader – and neither has NVIDIA. Enter the TNT2 M64 – the TNT2 for the masses.

A variety of "TNT2" cards are popping up all over the place with prices that seem too good to be true. But before you bite, check what you’re getting. The cards may be touted as a TNT2 or even a TNT2 "value," but many are the TNT2 M64, the card we are taking a look at today. Our goal here is to compare the M64 to the "real" TNT2.

• 125 MHz 128-bit 2D/3D core
• 2^nd Generation 128-bit TwiN Texel architecture
• 250 Megapixels per second
• 9 Million Triangles per second peak processing power
• Resolution support up to 2046 x 1536
• PCI/AGP Support – AGP 2X/4X Texturing Support
• 16/32-bit 3D Rendering Support
• 32-bit Z/stencil Buffer
• 300MHz Integrated RAMDAC
• 16/32MB 64-bit SDRAM
• 2048 x 2048 Texture Support
• Optional NTSC/PAL Video Out
• Optional Digital Flat Panel Output
• Direct3D/OpenGL API Support
• OpenGL ICD for Windows 9x, NT 3.5x, NT 4.0, and Windows 2000

So what makes the M64 different from the regular TNT2? For the most part, the M64 is identical to a regular TNT2. The 2D/3D cores are identical and, therefore, 3D image quality is the same. The RAMDAC is 300 MHz on both chips, so the same resolutions are supported. As it does with all TNT2 cards, 2D quality will vary from manufacturer to manufacturer. NVIDIA’s recommended clock speeds are also identical for the non-ultra TNT2 and TNT2 M64 – both at 125/150. However, because both are built on the same 0.25-micron process, identical clock speeds are not surprising at all.

It was originally thought that the M64 designation might indicate a TNT2 with support for 64MB of memory. Unfortunately, this was not to be the case as both chips support up to 32MB. Instead, the 64 in M64 refers to a memory bus that is 64-bits wide. The internal architecture is still 128-bit, just like the TNT2.

Back in the days of the original Matrox Millenium, 64-bit graphics were all the rage. However, today a 128-bit memory bus is the norm, like those used by the TNT, TNT2, and GeForce from NVIDIA and, consequently, the 64-bit looks poor in comparison. Just like the GeForce, it seems that the M64 is going to be severely limited by memory bandwidth, cutting it clock for clock by half in fact. The effects of reduced memory bandwidth would be borne out at higher resolutions and color depths. Of course, dropping down to a 64-bit interface reduces the cost of both chips and boards considerably, which is exactly why NVIDIA made such a compromise.