Tuesday, December 01, 2009

Intel i5-750, First Look

I now have my Intel i5-750 system up and running. This is the progress so far.

I have three very good processors to compare. I started with a three cored AMD X3 720 in my CoolerMaster Storm Sniper case with an Asus motherboard with AMD 785 chipset and 8 GB's of OCZ AMD gold edition memory (4 x 2 GB's). I never bothered changing to a third party cooler because the stock unit was adequate. I ran it with the integrated graphics which were not too bad but underpowered for games like Dawn of War. The thermal properties of this processor are good enough that I should be able to run it just fine in a small, tighter case with a moderate video card. I have handy a smaller case with neither front nor top fan (only the rear fan) and an HD 4650 video card. However, I do have an upgrade ready for the rear case fan if necessary. I'll probably end up running Linux on this system. The processor is rated at 95 watts TDP.

After the X3 720, I replaced the motherboard with an Asus board with AMD 79X chipset and 8 GB's of OCZ AMD Black Edition memory (4 x 2 GB's). The video was upgraded to an HD 5770 and the processor upgraded to Phenom II X4 965. This processor is the C3 stepping and is rated at 125 watts TDP. I also preferred a third party, Freezer 64 Pro cooler over the stock cooler. The stock cooler, in spite of the copper bottom and heat pipes, still blows hot air down on the board.

I have a second CoolerMaster case, a HAF 922. This has very similar front and top 200mm cooling fans with the same rear 120mm case fan. The box chasis is identical with the same drive bays in front. The power supply is a bit different. This system has a 700 watt CoolerMaster PS compared with the 850 watt Corsair PS in the Sniper case. However, neither power supply contributes to case heating or cooling because they both draw air from the case bottom and exhaust it out the back. My i5-750 is also rated at 95 watts TDP. I suppose the first question people might have is if it draws the same amount of power as the X3 720. No, it doesn't. Even at maxium overclock, the X3 720 barely throws any heat while the PII 965 throws a lot. The i5-750 is in between. It throws a great deal of heat at 3.4 Ghz, much more than the X3 720 does. If I were to make a rough estimate, I'd say the i5-750 must pull around 115 watts. This would put it a little closer to the PII 965 than the X3 720.

I've heard people say over and over that the Intel cooler is poor. It is actually quite a bit better than the stock X3 720 unit which has a smaller fan and no copper core. If the i5-750 really did draw as little power as the X3 720 then the heatsink would barely get warm. But this is not the case. Overclocked to even 3.4 Ghz, the heatsink blows hot air on the motherboard much more like my PII 965 than the X3 720. I'm sure there will be some skeptics who've read some whiz bang review somewhere that claims that is has accurately measured the CPU power draw at some incredibly low figure. Not a chance. The i5-750 undervolted to 1.12 volts still throws more heat at 3.4 Ghz than an X3 720 does at 1.325 volts and the same 3.4 Ghz. The X3 720 and i5-750 are absolutely not in the same thermal class.

So, Intel fudges the numbers? Yes. Does that bother me? No. Keep in mind that I'm not comparing the quad core i5-750 to the X3 720. That wouldn't make any sense because the X3 720 is much cheaper. No, I'm comparing the quad core, i5-750 to the similarly priced, quad core, Phenom II X4 965. The PII 965 is certainly not light on heat and, if the i5-750 can do the same amount of work, it doesn't have to be either. I have a very similar Freezer 7 Pro ready to install so I can at least stop the hot air blowing on the board. I'll add an update after I see how that works. You can see the pictures of the coolers below in my last article.

Note. I haven't switched to the Freezer 7 Pro cooler yet because I'm still trying to establish the baseline with the stock cooler. I have to admit that this is difficult for me. I didn't have any trouble pushing the X3 720 and PII 965 to their limits. And, when I knew what the limits were I accepted them. I ended up with 3.8 Ghz on the PII 965 and 3.4 Ghz on the X3 720. But, I tend to handle the i5-750 with kid gloves. It isn't easy being tough on i5 because doing thermal testing on an Intel Nehalem is like watching an eight year old trying to keep up with teenagers. Simply put, when I started holding the i5-750 to the same standards I used for my AMD processors, the i5 failed. So, I lowered the clock and tried again. I started at 3.6 Ghz then dropped to: 3.5, 3.4, 3.32, 3.154, and 3.078 Ghz without success. I was hoping it would pass at 2.988 Ghz but that just failed with an error. So, I'm trying again at 2.9 Ghz.

1 comment:

Troy said...
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