2. Processor

Choosing a processor for a new computer could drive anyone up the wall. Everyone in this position should first go and read Tom’s Hardware 2007 CPU roundup article. After that you will have adequate knowledge of the current state of the processor industry be in a position to understand the most useful cpu comparison tool on the net: The interactive 2007 CPU Chart.

The Intel Core 2 processors are definately faster and more overclockable than the AMD Athlon X2 processors. AMD knows this and has dropped their prices to such an extent, that even their flagships have radically low prices, making our decision all the more pliable. Its good to have options.

This situation will not change until new technologies are mainstreamed in mid 2008, which will reach maturity and affordable prices in 2009. Our options in this section are again wide open. I can choose either Intel or AMD processors for whatever motherboard I choose to go with in the end. Lets see what we can come up with to refine our options.

Cache Size

“Tom” said it best himself in this article. Cache size does make a difference that varies depending on the application. Since gaming is what we do, this table is worth a million words. The PCMark 2005 synthetic tests seemed to blur away the impact of higher cache, but most applications clearly benefit. We proceed knowing that synthetic benchmarks are insensitive to cache, but more is good.

Cache Size
4 MB
2 MB
1 MB
Quake4 (fps)
175 (+10.1%)
168 (+5.6%)
159
Prey (fps)
130 (+9.2%)
125 (+5.0%)
119
Call of Duty (fps)
85.7 (+0.9%) 
85.2 (+0.3%)
84.9
Winrar 3.7 (sec)
59.9 (+13.8%)
64.7 (+6.9%)
69.5
3DMax 8.0 (sec)
96 (-)
96 (-)
96
LAME (min)
174 (+.5%)
116 (+4.1%)
121
DivX 6.6 (sec)
113 (+6.6%)
116 (+4.1%)
121
XviD 1.1.3 (sec)
111 (+7.5%)
116 (+3.3%)
120
PCMark05 (system)
7292 (+4.0%)
7151 (+2.0%)
7012
PCMark05 (CPU)
6162 (+0.5%)
6138 (+0.2%)
6128
PCMark05 (memory)
5381 (+4.5%)
5150 (+0.3%)
5135
3DMark06 (Graphics)
9146 (+2.4%)
9081 (+1.6%)
8934
Core 2 Duo Extreme processor was clocked at 2.4 GHz. Performance percentage gains are wrt 1MB cache scores

Overall Performance Boost:

  • 4 MB L2 cache (wrt 1 MB) : 5.0%
  • 2 MB L2 cache (wrt 1 MB) : 2.4%

This table is a great resource in itself, as it contains the basic performance abilities of a Core2Duo processor at the average speed of 2.4GHz, with a “run-of-the-mill” Geforce 8800 GTS (nothing to sneer at of course) and a nice stable ASUS Blitz Intel P35 motherboard. It is also interesting to see how the testers balanced the speed of the three chips to make this table make sense. These are the processors used:

Pentium Dual Core E2160 65nm; 1200 MHz, 1 MB L2 Cache clocked at 2.4 GHz (266 MHz x9)
Core 2 Duo E4400 65nm; 2000 MHz, 2 MB L2 Cache clocked at 2.4 GHz (266 MHz x9)
Core 2 Duo X6800 65nm; 3000 MHz, 4 MB L2 Cache clocked at 2.4 GHz (266 MHz x9)

Thus these processors are equivalent when clocked at the same speed. They are all Core 2 Duo, 65nm process chips so that makes sense, you might say. What I’m really getting at though, is that with these chips, overclocking is exactly the same as having the more expensive processor. That means I’ll be hunting for the best overclocker/price I can find, without worrying about potential differences that come from the class of processor.

FSB

Lets start with a description of what the Front Side Bus is and does. The FSB is the speed that the CPU communicates with the memory. DDR2 memory has the ability to carry 4 pieces of information, simply speaking. The system clock is multiplied by the FSB to give the speed of the processor. The graphics card is also affected by the FSB so in overclocking projects it is preferable to drop the multiplier for a higher FSB frequencies, if possible.

Example: The Core 2 Extreme Processor QX6700 (2.66 GHz, FSB1066) is called Extreme, because Intel was kind enough to unlock its multipliers, which allows us to freely choose FSB and multiplier combinations. Thus the tender speed of 2.66GHz can be reached in two ways:

  • 266 MHz FSB x 10 multiplier = 2666 MHz, where the CPU sees 266 MHz FSB x 4 RAM cycles = 1033 MHz FSB
  • 333 MHz FSB x 8 multiplier = 2666 MHz, where the CPU sees 333 MHz FSB x 4 RAM cycles = 1333 MHz FSB

In the current market, FSB800 processors are dropping greatly in price and are mean overclockers. Next we have FSB1066 and FSB1333. I pointed this out in the motherboard section also. A nice and to the point Tom’s Hardware article below states that the average difference in their very comprehensive benchmark suite was less than 1%.

Tom’s Hardware: Less Than 1% Average Performance Gain At FSB1333 Vs. FSB1066

Choosing a processor for its higher FSB doesnt make sense, especially since several motherboard bios updates are adding 1066 and 1333 support to older chipsets. Therefore, the FSB is not something that is going to strongly affect your decision (or mine) so we can just ignore it and concentrate on something more important, such as how overclockable it is.

REMINDER: The motherboard must support the CPU at its operating frequency.

Favorites

Alas I have developped a favorite. Early overclocking reviews have it putting out around 4.2-4.5 GHz and it looks like it will become the new E6600. Cost is around $220 and dropping.

MY CHOICE :45nm process E8400 3GHz 6MB L2 cache Wolfdale : $220

X-Bit Labs: Meet the 45nm Intel Wolfdale family

Nordic Hardware: E8400 3.0GHz Wolfdale review

Below are other processors that caught my attention, with some of the reasons I picked them out.

Core 2 Duo E8400 3.06GHz Wolfdale 6MB L2 : $220

  • Overclocks hard, up to 4.5GHz on air for some.

AMD Athlon 64 X2 6000+ Windsor 3.0GHz : $160, PCMark05 6158

  • 4x customer award winner by Newegg, 5 eggs from 925 reviews.

Core 2 Duo E6750 2.66GHz Conroe 4MB L2 : $190, PCMark05 6835

Intel Core 2 Duo E6300 1.86GHz : $171.99, PCMark05 4794

  • Decent Overclocker, will get close to 3GHz with good air

Pentium D 805 2.66GHz 1 MB L2: $ ??? Hard to find now

Intel Pentium E2180 Allendale 1.6GHz 1MB L2 : $74.99

  • Pros: I have had this for about 2 weeks now it plays everything I throw at it. I have it currently running at 3.0 Ghz (375×8) (thats a 87.5% overclock, which is nuts!) no problem, on stock voltage, the memory is at 937. Havent been able to get it to 3.2 on stock voltage, havent really tried. there’s no need though, this thing flies.
  • Other Thoughts: On PCmark05 I scored a 7600 on the cpu benchmark. If you go to toms hardware guide look at where that puts this cpu on the chart! Amazing!

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