Performance and value: HEXUS.bang4buck considerations
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 | AMD Phenom II X4 955 BE | AMD Phenom II X4 940 BE | Intel Core 2 Quad Q9550 | Intel Core i7 920 |
|---|---|---|---|---|
| HEXUS.PiFast normalised | 95.6 | 89.3 |
100 | 99.4 |
| POV-Ray normalised | 77.5 |
71.7 | 71.4 | 100 |
| ET: QW normalised | 99.1 | 96.9 | 100 | 97.2 |
| DivX + QuickTime normalised | 87.55 |
79.25 |
85.1 |
100 |
| Average normalised performance | 89.94 |
84.29 |
89.125 | 99.15 |
| Price | £199 |
£167 |
£210 | £235 |
| Value for money rating (marks per £100) | 45.2 |
50.47 |
42.44 | 42.19 |
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 920 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 is the best chip, winning two benchmarks and finishing very close to the leader in the other two. In particular, it wins the POV-Ray benchmark easily, pushing all other chips' ratings down.
The AMD Phenom II X4 955 BE and Intel Core 2 Quad Q9550 benchmark (comparatively) in very similar fashion, and the Phenom II X4 940 BE brings up the rear. 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, the Core i7 920 and Core 2 Quad Q9550 perform about the same. AMD's Phenom II X4 955 BE does better, because it's around £10 cheaper than the Q9550, but performs, on these benchmarks at least, the same. The slowest of the quartet, AMD Phenom II 940 BE, does best of all, because it now ships with an excellent etail price of around £167. Phew!
Long story short, Intel's Core i7 920 is the fastest CPU of this particular bunch. Take value and normalised performance into account and the two AMD chips look better.
