Overclocking, Power Consumption and Overall Impressions
Well, our tests revealed that AMD Quad FX platform cannot boast undefeated performance. Maybe it could be corrected by successful overclocking? Turned out it couldn抰. Our experiments showed that it is extremely hard and hardly efficient to overclock the Quad FX platform.
As we have already mentioned above, ASUS L1N64-SLI WS mainboard Quad FX platform is built on has quite a few overclocking friendly options for processor tweaking. Moreover, it allows increasing the clock generator frequency above the nominal value and adjusting the processor clock frequency multiplier that is unlocked by default by all Athlon 64 FX processors. We can even confirm that ASUS L1N64-SLI WS runs absolutely stably at 250MHz clock generator frequency. However, when it came to practical side of the Quad FX overclocking, we faced some issues.
Our test platform used two Athlon 64 FX-74 processors with 3.0GHz nominal clock speed. Unfortunately, we couldn抰 increase this frequency any further. If the clock generator frequency was set even 1MHz above the default 200MHz, the system wouldn抰 boot Windows XP shutting down automatically. It was pretty strange also because nothing could be done to resolve this situation: no common tricks used to improve the stability of the overclocked system, such as increasing the processor voltage, bus voltage or chipset voltage or lowering the HyperTransport bus multiplier, would help. We could free some room for the clock generator frequency increase by reducing the processor clock frequency multiplier below the nominal value, but only until the CPU frequency hit 3.0GHz. Once the frequency got higher, the situation repeated: the system would simply shut down on us.
Everything we have just said suggests that AMD, Nvidia or ASUS introduced some kind of protection into their system that prevents the CPU frequency from being increased above the nominal. Of course, it is really hard to believe especially since AMD has never prevented overclockers from having their fun, but it is an undeniable fact. It is even harder to believe that the CPU is working at the utmost of its potential in the nominal mode already.
Unfortunately, this is not all yet. Another huge problem of the Quad FX platform is its extremely high power consumption and heat dissipation. It is simply impossible even to compare it against anything else from this prospective. Of course a system built with two 90nm processors working at their maximum speed will anyway eat up more power than the competitor抯 solutions built with only one CPU (even a quad-core one) manufactured with finer 65nm process. Besides, the Nvidia nForce 680a SLI chipset also contributes a lot here, as it consumes much more power than any of the Intel chipsets.
To back up what we have just said, we measured the power consumption of the Quad FX platform (in the tested configuration) with two Athlon 64 FX-74 processors. Even in idle mode with enabled Cool抧扱uiet technology (without the monitor power consumption of course) this system consumed 192W of power, which is more than most contemporary systems would require for 100% workload. As for the maximum power consumption level, we managed to hit 501W when the system was running fully loaded. However, it is no secret that Quad FX systems can consume much more than that, because this time we didn抰 take into account the power consumption of the video subsystem, as it wasn抰 loaded at all. In other words, you will have to get a special powerful PSU for your Quad FX system, that抯 for sure.
Another problem directly connected with the power consumption is the level of generated noise. All this heat from the system should be dissipated somehow and this is when we often use traditional air-coolers. Without the graphics card Quad FX platform already has 5 powerful fans cooling the processors, the chipset and voltage regulators on the mainboard. Of course, there are at least a few additional case fans. And the coolers of the graphics cards and system PSU. So, there will be quite a few rotating parts in Quad FX platform for sure, so it should never be even considered quiet in the first place.
Here I would also like to add that you should make sure you抳e got the right case to accommodate your Quad FX system, far not any case will do the trick, because ASUS L1N64-SLI WS mainboard is relatively big and the system case should ensure proper cooling of all the components.
