System Builder Marathon: Overclocking
Overclocking The Low-cost System
Let's start off with the lowly Phenom, the only four-core budget CPU that got to participate in our marathon.
| Current SBM Low-Cost PC Component Cost | ||
|---|---|---|
| CPU | AMD Quad Core Phenom 9500 | $190.00 |
| CPU Cooler | Cooler master HyperTX 2 | $25.00 |
| Motherboard | Gigabyte GA-MA78GM-S2H | $100.00 |
| RAM | Wintec Ampo DDR2 PC2-6400 - 2 GB | $43.00 |
| Graphics | HIS Radeon 3870 ICEQ Turbo | $230.00 |
| Hard Drive | Western Digital Caviar 500 GB | $95.00 |
| Sound | Integrated high Definition Audio | $0.00 |
| Case | NZXT Apollo | $70.00 |
| Power | NZXT PP600W | $70.00 |
| DVD-RW | Sony Optiarc DVD-RW | $14.00 |
| Total Price | $837 |
When we chose the Phenom CPU for our low-cost PC, we intended it for people who aren't interested in overclocking; it's no secret that AMD's Phenom cores aren't great overclockers. In addition, while MicroATX motherboards like Gigabyte's GA-MA78GM-S2H offer great features for the price, they don't have great overclocking reputations either. Regardless, we proceeded with honorable intentions and the hope that we might have a lucky chip.
Fate had other plans however. Instead of a rare specimen, we ended up with the average run-of-the-mill Phenom 9500 CPU that everyone else got. 2.5 GHz is par for the course with the Phenom 9500, so we were neither surprised nor thrilled when our CPU topped out at 2.54 GHz.
The motherboard had all the basic stuff, and we could even access an advanced tweaker's version of the BIOS by hitting CTRL and F1 at the same time, but it didn't really help us all that much. We hit 2.6 GHz at first quite easily by raising voltages just a little, but repeated crashing in Prime95 let us know we were at the limit. Increasing the Phenom's voltage seemed to have the opposite effect we were hoping for as the CPU simply increased the frequency of failure. Strangely enough, the CPU core was kept nice & cool by the HyperTX 2, and the Phenom barely went above 50 degrees during torture tests.
So we settled for a final 2541 MHz CPU speed with voltage settings @ 2v on memory, 1.2v on the Northbridge, and 1.255 volts for the processor. This is certainly not anything worth celebrating, but we did what we could.
The really bad news is that the Radeon 3870, which overclocked admirably when the CPU was at stock speeds, refused to budge on the overclocked platform. This really hurt the overclocked game benchmarks as most of them are GPU limited, not CPU limited.
In any case, our sub-$200 quad-core CPU got us from 2.2 GHz to 2.54 GHz which, considering the Phenom's overclocking reputation and the MicroATX platform it was running on, is not all that terrible. The speed bump in applications is quite noticeable.
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Enough excuses! Off to the results.
