Overclock Experience on AMD FX-8350 CPU on ASRock 990FX Extreme9 Mobo Using 2400 Speed Memory

A few months ago I decided to sacrifice my AMD FX-8150 – re-purposing it as a decent 8-core virtual server instead. In its place I purchased one of the new AMD 7850K Kaveri APU’s. My former FX-8150 workstation had an Nvidia 670 graphics card and the system consumed a lot of power, even when barely being used for anything. The thought of a 95w Kaveri sounded great.

And it was – with the new Kaveri 7850K chip as my CPU/GPU (APU) and the Nvidia card removed, the system rarely consumed more than 65w (including an LCD 24″ monitor)! When I played the occasional game on it, or the odd video encode, the power would spike up to 150w easily enough, since I had it overclocked a bit. I love this little system and still keep it. But I found that there are times when I really need the raw horsepower I gave up with the FX-8150.

So I decided to purchase the newer AMD FX-8350 instead. Of course, this chip isn’t all that new, really. But after looking at various “not-just-mainstream-talking-head” benchmarks, and see it compared reasonably well with the much more expensive Intel offerings, even their latest and greatest, I decided to go with it. My old FX-8150 was so solid. I was hoping the FX-8350 would be the same, and give me a little more performance as well.

The Kaveri APU’s benefit greatly from very fast memory. The talking heads out there claim that the FX-series processors don’t benefit that much from faster memory, and many claim that the AMD memory controller can’t even handle faster memory speeds well, past 1866 MHz. I decided to purchase faster memory nevertheless, thinking I could always use it in the APU system, since I wasn’t that thrilled with the more bargain Team Group memory I purchased for it. So I bought the AMD Radeon Gamer series memory, 2 sticks of 8 gigabytes rated for 2400 MHz speed at a CAS latency of 11. Expensive, but I didn’t want to mess around this time, wondering.

I also bought the obligatory aftermarket CPU cooler: a Hyper 212 Evo. It’s a beast of a hunk of metal, but I kinda like that. And no matter what, I’m not putting water inside my computer. I’ll just keep the clock speeds down (and power consumption).

For the motherboard, I decided upon the ASRock 990FX Extreme9. I was going to go with the ASUS Crosshair V Formula-Z, but it was always out of stock at Newegg, and I’ve recently become more skeptical of ASUS’s quality. I only ever used ASRock boards one other time, for a router I was building, and the thing was a good price, and very solid. So why not? The Extreme9 even had the Intel NIC on it, and a 12x power phase, which is unheard of. So anyway, that’s the board I chose, and it was only $169 – while the FX-8350 I got for $179. 🙂 The 16G of 2400 memory was the most expensive of all at $199!

Anyway, to the point. That’s what I have, and why I got it. In this machine is also a Bluray SATA drive, 2 3T SATA hard drives, and 2 120G SSD’s. All of that, and one ASUS LCD monitor are plugged into a UPS to draw power. So I can see my power utilization. Not uber scientific accuracy of course, but close enough just to have a look-see. Oh and the big power draw (supposedly), I splurged on a new graphics card as well, an R9 290 OC – just to keep it in the family.

I shelled out the $100 to Microsoft as well to get a Windows 8.1 Pro OEM license. That always makes me happy.

This AMD FX-8350 machine does run very solid. Like a tank. Just like me FX-8150, I never can seem to bog it down in its responsiveness, no matter what I’m doing, including virtualization.

I don’t overclock that often, and don’t know a ton about it. However, I was surprised that I could easily get the AMD FX-8350 CPU up to 4.4 GHz and the memory up to the full 2400 MHz speed, all while just using the air cooling of the Hyper 212 Evo! It honestly shocked me.

Of course, that’s no big deal unless you are running the CPU at full throttle for a long period of time. And what better way to do that, than to encode HD video using Handbrake – which maxxes out every single core for hours on end. It was my test, both of thermals and voltages, as I fine-tuned things.

People get confused about CPU temperatures. There are 2 different kinds. There is the CPU temperature at the socket, and there is the CPU temperature of the CPU cores themselves, within the chip. Both temperatures have different manufacturer suggestions/limits.

Using the ASRock motherboard’s automatic overclocking setting to reach 4.4 GHz on the CPU and 2400 MHz memory speeds, with handbrake running continuously my CPU core temperature maxxed out at 80c, and the thermal thresholds of the CPU cores reached AMD’s predefined limits, and the voltage automatically dropped at brief intervals to keep the temperatures below the supposed damage threshold.

So I thought, well, I should be able to lower the CPU voltage some, and the Northbridge voltage as well, and still be stable — and this should lower both my temperatures and power consumption. My thinking was, the motherboard manufacturer would want to pick voltages that were on the more greedy side to make sure the overclocks were more likely to work.

This proved to be a good move. I managed to lower the voltage on both the CPU and northbridge without sacrificing any performance, bringing the thermals down well below thresholds, and decreasing the power consumption by about 30 watts.

I’ll show you some screenshots I took while I was in the middle of running those Handbrake video encodes that kept the FX-8350 CPU cores pegged at full. The power draw you’ll see is reported from the UPS the system is plugged into. So here is a list of devices that are currently drawing power on that device:

  1. AMD FX-8350 CPU
  2. 2x8G AMD Radeon Gamer series memory @ 2400
  3. 6 120MM case fans
  4. Seasonic Gold something power supply 😉
  5. AMD R9 290 OC (MSI)
  6. Yeti microphone
  7. ASUS Bluray SATA drive (not actively spinning)
  8. 2 3T Seagate Barracuda hard drives
  9. 2 120G SSD drives (Samsung and OCZ V4)
  10. ASUS VN247 LCD monitor

All of that, with the CPU pegged out and overclocked to 4.4GHz, the system was drawing 307 watts! Of course, if the graphics card were going like crazy, it would be significantly more. But that just amazes me how little that graphics card will draw, too, when it’s not being used except for dual-monitor 1080p (one monitor is plugged into that UPS while the other isn’t).

When the system is idle but awake, just doing its normal system-y things in the background, all those things draw 121 watts with the CPU at 4.4 GHz still. Absolutely nuts! That’s some amazingly good power-awareness work, in both the CPU and video card.

As you can see from those screenshots, there is the idle power draw and the fully loaded CPU power draw running maxed-out FX-8350 on all 8 cores. Also, the AMD Overdrive screenshot shows those cores all maxed out, along with the “thermal margin”. This “thermal margin” value is often confusing to people it seems. It represents the number of degrees you have left to heat up before you reach AMD’s predefined maximum safe temperature per core. By lowering voltages I was able to give myself a comfortable thermal margin while still maintaining a completely stable 4.4 GHz overclock that ran and ran and ran.

The “ASRock Extreme Tuning Utility” screenshot shows ASRock’s included software overclock utility that came with this 990FX Extreme9 motherboard. It’s not the greatest utility – but it’s ok for tweaking some things. The BIOS is the place to do it, and the boot-to-UEFI feature is great. I am incredibly pleased with this motherboard. The ASUS stuff has seemed so buggy lately. I am convince that there is no way I could have gotten such a stable overclock with such low voltages were it not for this fine board (and perhaps the silicon dye god’s favor).

The last screenshot above is the CPUZ utility showing the memory speed and timings, in case someone doesn’t believe that an FX-8350 can run with 2400 speed memory. There it is! It’s using those AMD memory modules, though.  And if you look at the northbridge speeds in the ASRock utility screenshot, you’ll see that the bandwidth is there. I could probably even press it further. Haven’t tried yet, though. It most certainly increased my AIDA64 scores below. The AMD chips, even the FX ones, actually do seem to benefit from fast memory.

All in all, I’m extremely happy and surprised by this system. I’m also impressed with the memory bandwidth AMD has provided even on the FX series processors. I had an evaluation copy of the AIDA64 test suite, and included the benchmark results below.

What astonishes me is that there are cases where this FX-8350 CPU greatly outperforms even the i7-4770k from Intel. Of course, there are cases where the Intel i7-4770k CPUs outperform the AMD FX-8350 as well. The price difference between the two is huge, though, especially when you take into account motherboards with comparable features.

I used to run i7’s several years ago, but switched to the FX processors after experiencing how much better the AMD chips handled virtualization. I have no benchmarks, but using the systems I could certainly feel the difference. And virtualization is a lot of what I do. Playing games, I can never tell the difference. But if I’m playing a game on a system that’s running some load in a virtualized environment at the same time, the AMD system runs smooth, while the i7 system acts choppy. That’s why I switched.

But all silly Intel vs. AMD stuff aside, if I look at just this chip, and even the small overclocking up to 4.4 GHz, I can certainly notice a huge performance gain while transcoding video with Handbrake. I have also noticed that running the memory at 2400 MHz most definitely improves the responsiveness of the system, such that I can’t even tell when I’m running with all the cores maxxed out.

Honestly, I was a little hesitant about going with the FX-8350 chips, since they are older than the newest releases from Intel. But right now, I have absolutely no regrets. They are still amazingly great performing workhorses and absolutely rock solid. Especially if you invest in the quality components.

AIDA64 Extreme benchmark test results:

Anyway, I hope you have found something useful in all this. It’s hard finding any more detailed information out there related to specific use cases and experiences.

I’m so pleased with this purchase and have absolutely no regrets about spending the money for the quality components. And no regrets about not spending twice even that much for an Intel-based system.

Besides the incredible solidity of this system, the thing I’m most impressed with is how well it utilizes power. Although the FX-8350 chip isn’t the most power-efficient chip, it’s not bad for an 8-core! And it seems like AMD has gone to some great lengths to only draw power when you really need it, whether it’s a CPU or a GPU. I swear that R9 290 isn’t drawing any power it seems. You do see it when you’re gaming though.

Oh, and I should mention, I overclocked this while leaving Cool and Quiety enabled in the UEFI, and also C6 state on the CPU, which gives it the ability to save lots of power. This has not impacted the stability of the overclock at all. Then again, I’m hardly pushing this chip to anything close to what it’s capable of, either.

Anyway, just thought I’d share my happiness and enthusiasm in case you might be questioning similarly.

BTW – the hardware support for AES encryption on this chip is phenomenal. Encrypted disks and folders? No worries. 😉