Usability ratings are calculated by the following formula:

Kuse = ((((C10xp*0.6 + C12xp*0.3 + P¡16xp*0.1) +
      (HL10xp*0.6 + HL12xp*0.3 + HL16xpxp*0.1) +
      (G210xp*0.6 + G212xp*0.3 + G216xp*0.1) +
      (TRAOD10xp*0.6 + TRAOD12xp*0.3 + TRAOD16xp*0.1) +
      (FC10xp*0.6 + FC12xp*0.3 + FC16xp*0.1))* 3 ) +
      (RM10xp*0.6 + RM12xp*0.3 + RM16xp*0.1))* 3 ) +
      (D310xp*0.6 + D312xp*0.3 + D316xp*0.1))* 3 ) +
      (PK10xp*0.6 + PK12xp*0.3 + PK16xp*0.1))* 3 ) +
      (C10aaaxp + HL10aaaxp + G210aaaxp + TRAOD10aaaxp + RM10aaaxp + FC10aaaxp + D310aaaxp + PK10aaaXP) * AAA) * 0.7 +
      (Poss * 0.3)) * 20/ (Price + APG)

The similar calculation (but for 1600x1200 resolution only) indicates the prospect of a videocard. The formula contains the same indexes as those used for usability rating calculations, but accelerator's price isn't considered. So, this rating indicates the capabilities of the current 3D cards in the current applications and future games.

Kpro = ((P¡16xp +
      HL16xpxp +
      G216xp +
      TRAOD16xp +
      RM16xp+
      D316xp+
      PK16xp+
      FC16xp)* 0.7 +
      (Poss * 0.3)) * 2 / 2

You can also compare two ratings to see the correspondence of product prices to their capabilities and features.

Sergey Gajdukov suggested the nonlinear relation calculation method, which we use now (it's also provided in Excel table). Kuse is calculated using the similar formula, but each FPS value is not entered as is, but calculated like shown below:

FPSnew = 50 * (ATAN (FPSold / 30 - 2) - ATAN (-2)) + FPSold / 100

This relation has the following properties:

1. In the 0..20 range FPSnew is much smaller than FPSold ("low performance penalty")
2. In the 20..60 range the following should be true: FPSnew < FPSold
3. In the 60..120 range both values are approximately equal, i.e. the function is almost linear.
4. At x > 120 the function should grow VERY slowly

Legend:

• Kuse - usability rating. The higher it is, the better card's mark is.
• Kpro - prospect rating. The higher it is, the better card's mark is.
• C10xp - speed in Call of Duty (ixbt0104) at 1024x768x32 (Windows XP);
• C10aaaxp - speed in Call of Duty (ixbt0104) at 1024x768x32 (Windows XP) and AA+Aniso;
• C12xp - speed in Call of Duty (ixbt0104) at 1280x1024x32 (Windows XP);
• C16xp - speed in Call of Duty (ixbt0104) at 1600x1200x32 (Windows XP);
• HL10aaaxp - speed in Half Life 2 beta at 1024x768x32 (Windows XP) at max. quality and AA+Aniso;
• HL10aaaxp - speed in Half Life 2 beta at 1024x768x32 (Windows XP) at max. quality and AA+Aniso;
• HL12xp - speed in Half Life 2 beta at 1024x768x32 (Windows XP) at max. quality;
• HL16xpxp - speed in Half Life 2 beta at 1600x1200x32 (Windows XP) at max. quality;
• G210xp - speed in Unreal 2 at 1024x768x32 (Windows XP);
• G210aaaxp - speed in Unreal 2 at 1024x768x32 (Windows XP) with AA+Aniso;
• G212xp - speed in Unreal 2 at 1024x768x32 (Windows XP);
• G216xp - speed in Unreal 2 at 1024x768x32 (Windows XP);
• TRAOD10xp - speed in Tomb Raider: The Angel of Darkness (Paris5_4 demo) at 1024x768x32 (Windows XP);
• TRAOD10aaaxp - speed in Tomb Raider: The Angel of Darkness (Paris5_4 demo) at 1024x768x32 (Windows XP) and AA+Aniso;
• TRAOD12xp - speed in Tomb Raider: The Angel of Darkness (Paris5_4 demo) at 1024x768x32 (Windows XP);
• TRAOD16xp - speed in Tomb Raider: The Angel of Darkness at 1600x1200x32 (Windows XP);
• RM10xp - speed in RightMark at 1024x768x32 (Windows XP);
• RM10aaaxp - speed in RightMark at 1024x768x32 (Windows XP) with AA+Aniso;
• RM12xp - speed in RightMark at 1280x1024x32 (Windows XP);
• RM16xp - speed in RightMark at 1600x1200x32 (Windows XP);
• FC10xp - speed in FarCry at 1024x768x32 (Windows XP);
• FC10aaaxp - speed in FarCry at 1024x768x32 (Windows XP), AA+ANISO;
• FC12xp - speed in FarCry at 1280x1024x32 (Windows XP);
• FC16xp - speed in FarCry at 1600x1200x32 (Windows XP);
• D310xp - speed in DOOM III at 1024x768x32 (Windows XP);
• D310aaaxp - speed in DOOM III at 1024x768x32 (Windows XP), AA+ANISO;
• D312xp - speed in DOOM III at 1600x1200x32 (Windows XP);
• D316xp - speed in DOOM III at 1600x1200x32 (Windows XP);
• PK10xp - speed in Painkiller at 1024x768x32 (Windows XP);
• PK10aaaxp - speed in Painkiller at 1024x768x32 (Windows XP), AA+ANISO;
• PK12xp - speed in Painkiller at 1280x1024x32 (Windows XP);
• PK16xp - speed in Painkiller at 1600x1200x32 (Windows XP);
• Price - card price for the end of the month taken from price lists of a number of companies (for an average card);
• APG - see above;
• Poss - estimated functional potential and quality of a videocard (see remarks below);

Poss is calculated by the following formula:

Poss = (2D*10 + Driver*70 + AF*6 + TLF + DOT3 + EMBM + CEM + AA*2 + S3TC + Glide + VS + PS + 3dc + DH) * 3

Where:

• 2D - estimated 2D graphics quality on the 100-mark scale;
• Driver - estimated drivers quality (including installation difficulties, etc.) on the 100-mark scale;
• AF - anisotropic filtering:
  • = 700 - RADEON 9600/9700/9800/X800, GeForce FX/6800;
  • = 0 - n/a;

• TLF - trilinear filtering:
  • = 600 - available;
  • = 200 - potentially available with resource losses;
  • = 150 - approximation;

• DOT3 - Bump Mapping DOT3:
  • = 600 - available;
  • = 0 - n/a;

• EMBM - Bump Mapping EMBM:
  • = 600 - available;
  • = 0 - n/a;

• CEM - Cubic Environment Mapping:
  • = 600 - available;
  • = 0 - n/a;

• AA - antialiasing (on condition of minimal gameplay):
  • = 700 - GeForceFX/6800 MSAA, RADEON 9700/9800/X800 MSAA;
  • = 400 - SSAA, RADEON 8500 SmoothVision;
  • = 0 - n/a;

• S3TC - texture compression:
  • = 600 - RADEON 9600/9700/9800/X800, GeForce FX/6800;
  • = 0 - n/a;

• VS - hardware vertex shaders:
  • = 800 - GeForce 6800;
  • = 700 - RADEON X800;
  • = 600 - RADEON 9700/9800, GeForce FX;
  • = 400 - GeForce 4, RADEON 9100;
  • = 0 - n/a;

• PS - hardware pixel shaders:
  • = 1000 - version 3.0;
  • = 900 - version 2.0b;
  • = 800 - version 2.0;
  • = 600 - version 1.4;
  • = 450 - version 1.3;
  • = 400 - version 1.1;
  • = 0 - n/a;

• 3dc - 3Dc mark obtained in the following way:
  
  
  • = 400 - available;
  • = 0 - n/a;

• DH - additional features: dual-monitor output with the support of DualHead/TwinView/HydraVision technologies, TV-tuner, etc.:
  
  
  • = 700 - RADEON 9600/9700/9800/X800, GeForce FX/6800;
  • = 0 - n/a;

P.S. We understand that such way of making ratings is not perfect, therefore we await suggestions and comments from our readers to be considered in our next 3Digest.