The value proposition and HEXUS.bang4buck
Value summaryWe can normalise performance of the chips by setting the fastest's result to '100' and then apportioning a figure for the other chips based on the relative performance. We've chosen to evaluate the value proposition over four benchmarks. A table should make this easier to understand:
| Chip name/benchmark | Intel Core i7 975 EE | Intel Core i7 965 EE | Intel Core i7 920 | Intel Core 2 Quad Q9650 | Intel Core 2 Quad Q9550 | AMD Phenom II X4 955 BE | AMD Phenom II X4 940 BE |
|---|---|---|---|---|---|---|---|
| HEXUS.PiFast normalised | 100 | 91.3 |
75 |
79.1 |
74.3 |
71.1 |
66.4 |
| POV-Ray normalised | 100 |
95.2 | 79 |
57.1 |
53.8 |
58.4 |
54.1 |
| ET: QW (1680x1,050) normalised | 96 | 95.2 |
96.5 |
100 |
99.3 |
98.4 |
96.3 |
| DivX + QuickTime normalised | 100 |
93.6 |
77.2 |
66.5 |
62.2 |
63.5 |
59.2 |
| Average normalised performance | 99 |
93.82 |
81.93 |
75.68 |
72.4 |
72.85 |
69 |
| Price | £899 |
£775 |
£225 | £250 | £199 |
£187 | £148 |
| HEXUS.bang4buck rating (marks per £100) | 11.01 |
12.11 |
36.41 |
30.27 |
36.38 |
38.96 | 46.62 |
The benchmarks and normalisation
The first, HEXUS.PiFast, helps us to understand single-threaded performance, which still makes up the throughput of a large number of applications. Secondly, we've taken account of POV-Ray, as it provides near-perfect scaling with cores and threads, such that the performance in this benchmark is with the processor working at close to 100 per cent: an ideal scenario. Thirdly, we look at gaming at 1,680x1,050, to see how the chips fare when the IQ is set to a decent level. Lastly, we look at DivX performance with a QuickTime clip in the foreground - a kind of multi-tasking, if you will.
We then derive an averaged normalised figure based on the four results, with the leading chip set to 100 at all times. In effect, we're looking at the percentage performance of any chip when the fastest chip is locked to 100. So, for example, if the Intel Core i7 975 EE is the fastest in a particular benchmark and scores 150fps, a chip scoring 75fps would receive a normalised score of 50 marks.
Analysis
The average normalised performance shows how well the CPUs have done on a cumulative basis. The closer the score to 100 the better they are in each benchmark, which is weighted the same. Using this rationale, the Intel Core i7 975 EE is the best chip, winning three benchmarks and finishing very close to the leader in the GPU-bound ET:QW test. In particular, it wins the POV-Ray benchmark easily, pushing all other chips' ratings down, but is never more than 2x quicker than the cheapest and slowest.
However, if we then evaluate the average normalised performance with price, by stating how many marks each one receives on a '£100 basis' - an arbitrary figure - we see that, at current pricing levels, excluding platform costs, the Core i7 975 EE, whilst fastest, offers pathetic value for money, coming in last with a score of 11.01. The Core i7 920 is a much, much better value-for-money deal, scoring 36.41, but AMD's £148 Phenom II X4 940 BE does best of all. It's the slowest, yes, but you can buy six of them for one i7 975 EE!
