Once initial tests were finished we set about seeing whether we could overclock the 8750 and find out if it was actually a lamb dressed as mutton, so to speak.
Being as the 8750 is multiplier locked, the only overclocking we could do revolved around how far we could push the HyperTransport (HT) base frequency, which by default is set at 200MHz (12x200MHz = 2.4GHz). Starting with default voltages we very quickly hit a brick wall; because increasing the HT frequency also affects the memory speed, we had to reduce the memory multiplier (reducing the memory speed from 1066MHz to 800 MHz) before we could raise the HT frequency at all. Considering this is a problem Leo also encountered while reviewing the Sapphire PC-AM2RX780, it’s fair to assume it’s common across all Phenom setups.
Once we got passed this little set back we left all the voltages as default and started cranking up the HT frequency and got straight up to 240MHz (2.88GHz) without too much trouble. However, pushing much further required boosting the core and HyperTransport voltages. Unfortunately, while we could push further by upping the voltages, we never seemed to be able to maintain stability and eventually we settled on our original maximum of 2.88GHz for testing.
* AMD Phenom X3 8750 @ 2.4GHz (12 x 200MHz)
* AMD Phenom X3 8750 @ 2.88Hz (12 x 240MHz)
* AMD Phenom X4 9850 Black Edition @ 2.5GHz (12.5 x 200MHz)
* AMD Phenom X4 9600 Black Edition @ 2.3GHz (11.5 x 200MHz)
* AMD Athlon X2 5200+ @ 2.6GHz (13 x 200MHz)
* Intel Core 2 Quad QX9770 @ 3.2GHz (8 x 400MHz)
* Intel Core 2 Quad Q6600 @ 2.4GHz (9 x 266MHz)
* Intel Core 2 Duo E6700 @ 2.66GHz (10 x 266MHz)
* Intel Core 2 Duo E4300 @ 1.8GHz (9 x 200MHz)
Looking first at the single core results, it’s clear that the 8750’s relatively low clock speed hampers its performance and it’s soundly beaten by the faster clocked dual-core CPUs from both Intel and AMD. Once overclocked it does catch up with the rest of the pack but then all the other CPUs on test can also be overclocked to pull further ahead. Clearly then if performance of single threaded programs is your priority, the X3s aren’t the best choice.
Multithreaded applications, on the other hand, are where the X3 really shows its prowess – in all but the mp3 encoding test the X3 is markedly faster. There is one caveat to consider with these results, though. As yet some multithreaded software is not able to run properly on three cores because it has been designed to allow for multiples of 2 cores, i.e. 1, 2, 4, 8, etc. Of course most software will be retrofitted to enable triple-core optimisation but for the time being you may find your favourite program doesn’t get the performance boost you were expecting.
The final point to consider is that of multi-tasking. It’s all very well talking about multi-threaded software but for many people the advantage of three cores over two is simply that doing many things at once will be quicker. I for one often push my aging dual-core work PC to the limits by having tens of programs running at once so dropping a few megahertz in raw speed but having an extra core would be a tempting proposition for me.
Unfortunately, though, there’s no getting past the price. At their current prices the X3 range just aren’t competitive. Were the 8750 to be around £110 then it would be a good choice and if AMD could push it down as far as £100 then it would come highly recommended.
AMD’s triple-core X3 Phenom CPUs offer an interesting alternative to the traditional dual- and quad-core products. However, the price is just a little bit too high for us to recommend them right now. Once they hit £100-£110, though, then you’re looking at a great buy.