Power Consumption / Temperature Testing
System Power Consumption
Our power consumption numbers are broken down into two categories: one which simply stresses all of the CPU cores with WPrime and another which puts a high amount of load on both the CPU cores and the IGP. The latter will only be included if a given processor includes a dedicated internal graphics sub-processor.
For the CPU power consumption test, we use the standard testing system (with an NVIDIA GTX 670 installed) and wait until the system and discrete GPU are at idle speeds in order to log the idle power consumption. After this, WPrime 1024M is looped for 15 minutes while the power consumption is logged with a calibrated power meter to determine the peak watts.
Please note that after extensive testing, we have found that simply plugging in a power meter to a wall outlet or UPS will NOT give you accurate power consumption numbers due to slight changes in the input voltage. Thus we use a Tripp-Lite 1800W line conditioner between the 120V outlet and the power meter.
With a TDP of about 220W, it the FX-9590’s chart-topping performance shouldn’t come as any surprise. Pushing the 32nm Piledriver architecture to 4.7GHz (or 5GHz in some situations) takes a fair amount of voltage and no small amount of excess PSU capacity. As a result, the FX-9590 requires about 70W more power than an FX-8350 while the current generation Haswell processors aren’t even in the picture.
Unfortunately this leads to AMD’s latest processor having an extremely poor performance per watt ratio, even when compared against Sandy Bridge-E competitors.
The FX-9590 is a hot running processor and we don’t mean hot in any conventional meaning of the word either. This thing is like having a miniature nuclear reactor strapped to your motherboard; it will thoroughly overwhelm mid-tier heatsinks and AIO water coolers alike. Since it doesn’t come with an included heatsink we’re told that retailers will endeavor to bundle the FX-9590 with high end Corsair, Cooler Master or NZXT water cooling units in an effort to ensure customers won’t damage their new processors with sub-par cooling solutions.
With the potential for astronomical heat output, one would hope for an adequate way to measure temperatures. That just didn’t happen. RealTemp and CoreTemp routinely showed overly low readings and even AMD’s vaunted Overdrive utility was completely out to lunch. It claimed the chip idled at 19°C (ambient temperature was 23°) while load temperatures supposedly hit 46.7°C under load even though our Noctua NH-U14S was hot to the touch.
Only ASUS’ AI Suite II (which takes its temperature readings directly from the BIOS) was somewhat accurate with its reading of 65°C under load but we had reasons to doubt this too since, as you see in the screenshot above, our FX-9590 began throttling some cores down to the 4.515GHz mark after 20 minutes or so of continual full-load testing. Another possibility is that AMD has set Turbo Core 3.0 to begin throttling downwards when core temperature hits that 65°C mark in an effort to cap thermals and power consumption.
The lack of accurate temperature logging software poses a large problem for anyone with one of these 220W TDP chips: they have no way of knowing how hot (or cool) their processor is running. Not only will this play havoc when trying to dial in overclocks but it makes trouble-shooting stock issues all that much harder.