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i3DSpeed, March 2011

Usability and prospects ratings calculation method.

Andrey Vorobiev; April 8, 2011.

Ratings are calculated with the following assumptions:

  1. Demand for performance and quality:
    • Performance — 60%
    • Quality — 40%
  2. Only the highest resolution available in a game is used to calculate prospects ratings.
  3. Usability rating indicates card's performance and features relative to its price.

We have made significant changes to the rating calculation method for several reasons. Firstly, there was a number of math errors, so we decided to use geometrical average for all test results. Secondly, the quality value had little to no influence on the results. This was unacceptable due to newer games, in which AA or AF are very important. Thus we made AA and AF influence floating. The geometrical average performance is divided by 60 FPS (as a standard of average minimal sufficient performance) to obtain a coefficient of suitable performance. It's multiplied by a pre-fixed AA or AF coefficient that depends on certain card specs. This gives us a coefficient of card's AA or AF potential, that we finally take into consideration. Otherwise top-end cards would be underestimated, because when you spend $400-500, you get not only the FPS in existing games, but some potential for some higher quality in the future. Otherwise $10 cards made in 2002 could get high marks due to their low price).

Usability ratings are calculated by the following formula:

Kuse = ((K-no-AAA )^(1/36))^0.6 * ((Poss^0.4)) / (Price)) * 1500

Where:

  • K-no-AAA considers performance without AA+AF.
    K-no-AAA = (CR412xp * CR416xp * CR419xp * CR425xp) *
    (FC12xp * FC16xp * FC19xp * FC25xp) *
    (AVP12xp * AVP16xp * AVP19xp * AVP25xp) *
    (F112xp * F116xp * F119xp * F125xp) *
    (TR12xp * TR16xp * TR19xp * TR25xp) *
    (H212xp * H216xp * H219xp * H225xp) *
    (3DM1112xp * 3DM1116xp * 3DM1119xp * 3DM1125xp) *
    (DI12xp * DI16xp * DI19xp * DI25xp) *
    (ME12xp * ME16xp * ME19xp * ME25xp)
  • K-with-AAA considers performance with AA+AF. Calculated using the same formula with AA+AF performance values.

A similar calculation exclusively for the 2560x1600 resolution indicates card's prospects. The formula contains the same indexes as those used for usability rating calculations, but card's price is not considered. So, this rating indicates card's capabilities in current applications and future games.

You can also compare two ratings to see how prices correspond to capabilities and features.

According to the same scheme, but excluding 3DMark test results, we calculate K-no-AAA-only-games and K-with-AAA-only-games coefficients for gaming ratings.

Variables:

  • Kuse — usability rating, the higher it is the better
  • Kpro — prospects rating, the higher it is the better
  • FC12xp — Far Cry 2 at 1280x1024x32
  • FC16xp — Far Cry 2 at 1680x1050x32
  • FC19xp — Far Cry 2 at 1920x1200x32
  • FC25xp — Far Cry 2 at 2560x1600x32
  • TR12xp — Unigine Tropics Benchmark at 1280x1024x32
  • TR16xp — Unigine Tropics Benchmark at 1680x1050x32
  • TR19xp — Unigine Tropics Benchmark at 1920x1200x32
  • TR25xp — Unigine Tropics Benchmark at 2560x1600x32
  • H212xp — Unigine Heaven Benchmark DX11 at 1280x1024x32
  • H216xp — Unigine Heaven Benchmark DX11 at 1680x1050x32
  • H219xp — Unigine Heaven Benchmark DX11 at 1920x1200x32
  • H225xp — Unigine Heaven Benchmark DX11 at 2560õ1600õ32
  • 3DM1112xp — 3DMark 11 at 1280x1024x32
  • 3DM1116xp — 3DMark 11 at 1680x1050x32
  • 3DM1119xp — 3DMark 11 at 1920x1200x32
  • 3DM1125xp — 3DMark 11 at 2560x1600x32
  • DI12xp — Colin McRae: DiRT 2 at 1280x1024x32
  • DI16xp — Colin McRae: DiRT 2 at 1680x1050x32
  • DI19xp — Colin McRae: DiRT 2 at 1920x1200x32
  • DI25xp — Colin McRae: DiRT 2 at 2560x1600x32
  • ME12xp — Metro 2033 at 1280x1024x32
  • ME16xp — Metro 2033 at 1680x1050x32
  • ME19xp — Metro 2033 at 1920x1200x32
  • ME25xp — Metro 2033 at 2560x1600x32
  • JC12xp — Just Cause 2 at 1280x1024x32
  • JC16xp — Just Cause 2 at 1680x1050x32
  • JC19xp — Just Cause 2 at 1920x1200x32
  • JC25xp — Just Cause 2 at 2560x1600x32
  • AVP12xp — Aliens vs. Predator DX11 at 1280x1024x32
  • AVP16xp — Aliens vs. Predator DX11 at 1680x1050x32
  • AVP19xp — Aliens vs. Predator DX11 at 1920x1200x32
  • AVP25xp — Aliens vs. Predator DX11 at 2560x1600x32
  • F112xp — F1 2010 at 1280x1024x32
  • F116xp — F1 2010 at 1680x1050x32
  • F119xp — F1 2010 at 1920x1200x32
  • F125xp — F1 2010 at 2560õ1600õ32
  • CR412xp — Crysis Warhead Cargo DX10 at 1280x1024x32
  • CR416xp — Crysis Warhead Cargo DX10 at 1680x1050x32
  • CR419xp — Crysis Warhead Cargo DX10 at 1920x1200x32
  • CR425xp — Crysis Warhead Cargo DX10 at 2560õ1600õ32
  • Price — card's average price for the end of the month
  • Poss — estimated card's functional potential and quality

Poss is calculated by the following formula:

Poss = ((AF * AA)^(1/2) * (Driver * VS * PS)^(1/3)) / 100

Where:

  • Driver — estimated driver quality (including installation difficulties, etc.) on the 10-point scale.
  • AF — anisotropic filtering:
    • = 500 * (K-with-AAA^(1/68)) / 60 fps — Usual AF (GeForce 7xxx);
    • = 1000 * (K-with-AAA^(1/68)) / 60 fps — High-quality AF (GeForce 8xxx/RADEON x1xxx);
    • = 1500 * K-with-AAA^(1/68)) / 60 fps — Highest-quality AF (RADEON 5xxx/GeForce GTX 4xx and newer);
  • AA — antialiasing (on condition of at least minimal gameplay):
    • = 1000 * (K-with-AAA^(1/68)) / 60 fps — MSAA;
    • = 2000 * (K-with-AAA^(1/68)) / 60 fps — MSAA+SSAA;
    • = 2200 * (K-with-AAA^(1/68)) / 60 fps — MSAA+SSAA+TAA;
    • = 2500 * (K-with-AAA^(1/68)) / 60 fps — MSAA+SSAA+TAA+CSAA;
  • VS — hardware vertex shaders:
    • = 5 for version 5.0;
    • = 4 for version 4.0;
    • = 3 for version 3.0;
    • = 2 for version 2.0;
  • PS — hardware pixel shaders:
    • = 5 for version 5.0;
    • = 4 for version 4.0;
    • = 3 for version 3.0;
    • = 2 for version 2.0;

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