This is what happen in my mind for awhile now and thank God, the Sandy Bridge SATA issue save me for a while from making pretty tough decision.
However, since I already made the chart, I think it is nice to share with the world.
I am using Phenom 955BE right now and I am wondering either i7 2600k is a worth upgrade. If the answer is yes, how about i5 2500k. Although it doesn’t has the additional (HT) 4 threads, in most benchmarks it performs pretty well compare to his bigger sibling. And don’t forget, it is also significantly cheaper than i7 2600k too. So, if I take price into account, which one has more performance per money?
So, I fire up Microsoft Excell, get performance data from Tomshardware.com CPU chart and include current price for all the three CPUs, here are the outcome.
Chart 1: Relative Performance. Normalize to 100%
The graph above shows relative performance for each processor compare to the one that score the highest. This graph could be read from different angle. But personally I prefer to read it this way. If i7 get 100%, i5 get 75% and Phenom get 50% for benchmark A, it mean, i7 is 50% faster than i5 and 100% faster than Phenom 955BE. Otherwise, it could be read, Phenom 955BE only has half i7 power and i5 has only 3 quarters of i7 power. These number (in my explanation is just an example, regarding on how to read the graph. For actual number, please refer to table 1 (below).
Chart 2: Performance over Price
This graph (above) shows these CPU’s relative performance vs their own price. The one that has highest performance over price ratio, get 100%.
Chart 3: Performance vs Price (i7 vs i5 only)
Same as second graph but without Phenom 955 BE. A bit easier to compare which one has more bang for bucks between i7 and i5.
i7 2600k definitely has significant performance advantage over i5 2500k as shown in graph 1. However, if we consider i7 and i5 price, i5 has better performance per money as shown in graph 3. Interestingly, the most sensible purchase is Phenom 955BE (for performance over money : comparison of this trio). So, if you want the best of the best, rest assure that i7 is fast enough to differentiate its status compare to i5. However, if ultimate performance is not your aim, but you look for balance and sensible purchase, i5 is your best bet. Last but not least, if you plan to buy Phenom 955BE, I am happy to report that you gonna get most from your money.
As for my case, I might on hold my i7 2600k purchase until Intel solve P67 chipset issue. Its performance for multi-threading applications (where I expect more and more aps in the future will support more than 4 threads) + I am moving from 4 threads to 8 threads processor, give me enough reason to purchase i7 2600k. Graph 4 shows what I will gain if I upgrade my Phenom 955BE to i7 2600k. (This graph doesn’t take price into account)
Table 1: Raw Score
Table 2: Convert ‘less is better’ to normalize score=
Table 1: Performance Over Price (Normalize to 100)