Recently I had a brief discussion with some of my friends about the best CPU to start a build with. Generally there are two ways to think about "the best CPU." The first way is the "budget way." Starting with a total system budget, you find your CPU budget and then pick the best CPU within that budget. This is commonly seen in the System Builder's Marathon. Alternatively, one can find the best performance value chip on the market, then build a system around it. With the first method, you're best off just reviewing the last "Best Gaming CPU for the Money." The latter method required a bit more analysis.
First I have to define a few concepts. The first is that "performance" in the abstract is meaningless. Performance to a graphic designer is different from performance to a folding@home team is different from performance to a gamer. Because I don't have the time or the wherewithal to build my own 'performance' index, I used PassMark from CPU Benchmarks. This will probably invite methodological criticism, what can I say. Also, value is a nebulous concept because prices vary pretty dramatically between vendors. For this study, I used MicroCenter, because it's prices are consistently the lowest (Sorry newegg). Using a $289 price for the i7-920 would have skewed results pretty differently.
The first piece was pretty straightforward, I took the most of the popularly cited gaming CPU's from Tom's Hardware and found their PassMark/Dollar Ratio. Unfortunately, the AMD flagship, the Phenom II X4 965 BE is only $180, meaning that the $180+ sections of the graphs are exclusively Intel. It's not surprising considering that Intel is about a generation or two ahead of AMD technology-wise (just look at process node and energy efficiency).
Looking at all the chips overclocked would have been interesting, and may have shifted the price value a bit (especially clarkdales), but I intended this to be useful for non-overclockers as well. I did include overclocking data on two chips, the i7-920 and the X2 555 BE. Why those two chips? Given that the i7-920 with air cooling can match the performance of chips costing 4 times as much, I felt it was worth including. The Stock Phenom II X2 555 BE is quite frankly a very bad value. At the $100 price point, it is trounced by every other chip I looked at (i3-530 and X4 630). However, as noted in many other places, many if not most 555's can be unlocked to a Quad Core running at a stock rate of 3.2 GHz. I used a 955 as its proxy. An unlocked X2 555 BE is the best value in current CPU's, period, end of story.
To make the results more interesting, I added a "theoretical Thuban", the Phenom II X6 1055T. Without any data other than the clock rate (2.8 GHz), I took the results for the Phenom II X4 925 @ 2.8 GHz and simply scaled it by 50% (6 cores vs. 4 cores)... of course this is very rough, many of the benchmarks probably won't scale, but it is ballpark. The first takeaway, is that at 5100 PassMarks, the Thuban isn't a beast relative to Intel. With 8 logical cores, and an identical clockrate, an Intel i7-930 will walk all over it. Given it's likely performance is between that of the i5-750 and i7-920, AMD does not have a lot of leeway with respect to pricing. I threw out three prices, a low of $190 (placing it above the current flagship), a medium of $220 (above the i7-920), and a high of $260 (gouging people stuck on AM3?).
Here is the first chart... exceptionally good chips were highlighted:
Baring some unexpectedly high performance from the Thuban, to be competitive against intel, it will have to be a sub-$200 chip. Hard to believe a factory Hexacore being introduced for <$200, but above $200 it's simply eclipsed by stronger Intel chips.
The big takeaway here is that the Phenom II X4's are a bad deal considering how close the performance is not far from <$100 chips and price is close to the i7-920
Even with Thuban, AMD won't reclaim leadership.
This piece is not intended to be the final word on price value. For many builders other factors come into play, power consumption, upgradability, motherboard costs, brand affinity. Truth be told, I'm an AMD guy, have been since my first build (an Athlon 850 Mhz in 1999). For a budget build, AMD still dominates, but once you commit to spending more than $150 on a CPU, Skip everything and go directly to the i7-920 (and stop). Historically, the $300+ cost for X58 mobo's strongly weighed in against the i7-920, but now motherboard costs are quite reasonable. Regarding upgrade pathway, the sub-$100 AM3 chips will have a pretty handsome upgrade to a ~3.8 Ghz hexacore chip in 2011. The i7-920 owner will be able to step up to a more reasonably priced gulftown in late 2011.
R Brent Mattis
First I have to define a few concepts. The first is that "performance" in the abstract is meaningless. Performance to a graphic designer is different from performance to a folding@home team is different from performance to a gamer. Because I don't have the time or the wherewithal to build my own 'performance' index, I used PassMark from CPU Benchmarks. This will probably invite methodological criticism, what can I say. Also, value is a nebulous concept because prices vary pretty dramatically between vendors. For this study, I used MicroCenter, because it's prices are consistently the lowest (Sorry newegg). Using a $289 price for the i7-920 would have skewed results pretty differently.
The first piece was pretty straightforward, I took the most of the popularly cited gaming CPU's from Tom's Hardware and found their PassMark/Dollar Ratio. Unfortunately, the AMD flagship, the Phenom II X4 965 BE is only $180, meaning that the $180+ sections of the graphs are exclusively Intel. It's not surprising considering that Intel is about a generation or two ahead of AMD technology-wise (just look at process node and energy efficiency).
Looking at all the chips overclocked would have been interesting, and may have shifted the price value a bit (especially clarkdales), but I intended this to be useful for non-overclockers as well. I did include overclocking data on two chips, the i7-920 and the X2 555 BE. Why those two chips? Given that the i7-920 with air cooling can match the performance of chips costing 4 times as much, I felt it was worth including. The Stock Phenom II X2 555 BE is quite frankly a very bad value. At the $100 price point, it is trounced by every other chip I looked at (i3-530 and X4 630). However, as noted in many other places, many if not most 555's can be unlocked to a Quad Core running at a stock rate of 3.2 GHz. I used a 955 as its proxy. An unlocked X2 555 BE is the best value in current CPU's, period, end of story.
To make the results more interesting, I added a "theoretical Thuban", the Phenom II X6 1055T. Without any data other than the clock rate (2.8 GHz), I took the results for the Phenom II X4 925 @ 2.8 GHz and simply scaled it by 50% (6 cores vs. 4 cores)... of course this is very rough, many of the benchmarks probably won't scale, but it is ballpark. The first takeaway, is that at 5100 PassMarks, the Thuban isn't a beast relative to Intel. With 8 logical cores, and an identical clockrate, an Intel i7-930 will walk all over it. Given it's likely performance is between that of the i5-750 and i7-920, AMD does not have a lot of leeway with respect to pricing. I threw out three prices, a low of $190 (placing it above the current flagship), a medium of $220 (above the i7-920), and a high of $260 (gouging people stuck on AM3?).
Here is the first chart... exceptionally good chips were highlighted:
Baring some unexpectedly high performance from the Thuban, to be competitive against intel, it will have to be a sub-$200 chip. Hard to believe a factory Hexacore being introduced for <$200, but above $200 it's simply eclipsed by stronger Intel chips.
The big takeaway here is that the Phenom II X4's are a bad deal considering how close the performance is not far from <$100 chips and price is close to the i7-920
Even with Thuban, AMD won't reclaim leadership.
This piece is not intended to be the final word on price value. For many builders other factors come into play, power consumption, upgradability, motherboard costs, brand affinity. Truth be told, I'm an AMD guy, have been since my first build (an Athlon 850 Mhz in 1999). For a budget build, AMD still dominates, but once you commit to spending more than $150 on a CPU, Skip everything and go directly to the i7-920 (and stop). Historically, the $300+ cost for X58 mobo's strongly weighed in against the i7-920, but now motherboard costs are quite reasonable. Regarding upgrade pathway, the sub-$100 AM3 chips will have a pretty handsome upgrade to a ~3.8 Ghz hexacore chip in 2011. The i7-920 owner will be able to step up to a more reasonably priced gulftown in late 2011.
R Brent Mattis
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