AMD FX-8350 “Piledriver” Processor Review

Hot on the heels of our AMD A10-5800K Trinity APU Review, AMD announced the release of their next generation FX-series processors based on the new “Piledriver” cores today. Fortunately for us here at TechwareLabs, AMD sent us a shiny new FX-8350 to put through its paces and share our thoughts.

For those of you not aware, the new “Piledriver” based processors are the next evolution of the FX-series from the previous “Bulldozer” based processors. Unfortunately, the “Bulldozer” release was met with quite a bit of constructive criticism, as the hype and pre-release detail left a lot of folks underwhelmed. So, the immediate upside for AMD this go around is many people will be going into this release with more realistic expectations. However, the obvious questions still loom, are the “Piledriver” based processors worth a look and more importantly your money? Let’s dive in and find out.

Here is the new “Piledriver” FX-Series processor family:

The new “Piledriver” FX family isn’t as comprehensive as the previous generation from a selection standpoint, but appears to cover all the bases with 4, 6, and 8 core variants…all of which with relatively high clock rates. As with all FX processors, these are unlocked, so it will be interesting to see how much headroom is available for overclocking.

With this release AMD’s goal is quite simple, deliver a 15-20% improvement across the board over the previous generation and provide a cost attractive solution for multi-threaded environments and 1080p gaming, with a dash of overclocking capabilities to attract the enthusiast in all of us.  Well, with the FX-8350 specifically, the 8-core processor with a base clock of 4Ghz, sure seems to fit the bill on paper. Before we get into the testing, let’s take a closer look at what’s under the hood.

The FX-8350 is a 315mm² die manufactured on a 32 nm node and composed 1.2 billion transistors, which for those of you keeping track at home is the same as the previous “Bulldozer” generation. It continues to support the AM3+ based AMD 9-Series motherboards, so for some of you this will be a simple “drop-in” upgrade option.

With the new “Piledriver” cores, AMD was pretty forthcoming with the improvement and enhancements over “Bulldozer”. At the risk of making a “Captain Obvious” statement, all of these are aimed at the 15-20% improvement goal over the previous generation.

• Supports up to 8 cores and support for the latest ISA instructions including FMA4/3, AVX, AES, XOP
• Branch Prediction and L2 Cache optimizations over the previous “Bulldozer” cores
• Max Turbo Frequencies up to 4.2GHz
• Configurable via AMD OverDrive

Hardware Setup:

Test system:

• Motherboard:
  • Asus Crosshair V Formula (Socket AM3+) AMD 990FX/SB950 Chipset
• Processors:
  • AMD FX-8350 (Vishera) 4.0 GHz (20 * 200 MHz), Socket AM3+
  • AMD FX-8150 (Zambezi) 3.6 GHz (18 * 200 MHz), Socket AM3+
•  Memory
  • Kingston HyperX (KHX2133C9AD3T1FK4/8GX) 4GB (2x2GB) DDR3-2133
• Hard drive:
  • Crucial M4 256GB SSD
• Video Card:
  • Nvidia GeForce GTX 580 1.5 GB
• Power supply:
  • NZXT 1000W
• Cooling:
  • AMD FX closed loop water cooler (similar to the Antec Kuhler 920).
• Operating System:
  • Windows 7 Ultimate x64

In our tests, we will pit the FX-8350 against AMD’s previous “Bulldozer” based FX-8150 to see just how much of a performance gain the new cores really bring to the table. We will run a variety of synthetic tests, gaming, and we will also take a crack on finding a stable 24/7 overclock. Obviously with the overclock, some features will be disabled (i.e. Turbo core). All tests run will include for the FX-8150, FX-8350 (base), and FX-8350 overclocked.

Overclocking:

Before we get into the tests, let’s take a moment to discuss how well the FX-8350 overclocks. Not everyone is going to feel comfortable overclocking a CPU, mainly because the process can be more of an art then a science. However, I can say that some processors are easier to overclock then others, and right off the bat I can say that the FX-8350 is probably one of the easiest CPUs I have overclocked in sometime. This chip really seems comfortable running at higher clock speeds. So my plan was to find a stable 24/7 overclock that would require the least amount of additional voltage to the CPU and NB and stay around 50c under loads. There are many people that are comfortable overclocking their CPU’s with higher load temps, but at some point heat becomes your biggest enemy.

With a simple bump in ratio, and stock voltage I was able to get a stable 4.4Ghz (200×22) overclock, but ultimately was able to nudge the bus speed to 210 with a slight boost in CPU voltage (1.4) for a stable 4.6Ghz overclock that ran with almost no heat increase…which is almost perfect.

Now I did want to see how much I could push this CPU and where I was able to get stable overclocks of 4.8Ghz and 5.0Ghz, it the required voltage jumps nearing the high end (1.45/1.5 on the CPU). This ultimately lead to some really high load temps, that I was uncomfortable accepting as a 24/7 overclock. There just seemed to be a pocket at 4.8Ghz that required to much additional effort (voltage and cooling) to justify, which is why I kept coming back to the 4.6Ghz overclock as my particular “sweet spot” given my particular cooling setup(and this is running the fan on extreme…or leaf blower mode).

With the question of overclocking out of the way, it was time to run some benchmarks and see how things shook out.

With the overall score, the FX-8350 shows about an 8% increase over the FX-8150. I was sort of hoping for more here, but as you can see with the relatively simple low-risk overclock was about a 13% improvement. This was at least closer to my expectations, and it’s at least good to know that the additional performance is there if you’re willing (and capable).

The remaining individual suites seemed to mirror the overall in both percentages and trend, so at minimum the performance gains were consistent in the various benchmarks.

 

It appears there is very little difference in the Multi-core latency over the FX-8150. The efficiency across the board seemed unchanged over the previous generation…which was a bit of a surprise.

I am not sure what happened here with power management efficiency, but this is one suite that bucked the comparison trend between the FX-3850 and FX-8150. It was also interesting to see that the OC closed the gap a bit.

X264 HD Benchmark 5.01:

With x264, the higher the FPS, the better the performance and again we see the consistent performance trend seen in other benchmarks. Consistency really is key in my opinion, because consistent performance gains are better than niche areas where certain CPUs perform better than others, for overall value and performance.

CINEBENCH 11.5:

With synthetic benchmarks out of the way, it was time to see what the FX-8350 brought to the table over the FX-8150 for gaming. All of these games were set to 1920×1080, given the portion of the market this CPU is geared too, this should be the more predominant resolution used.  Additionally, the highest settings were always chosen for each title.

Dirt 3:

Here we see about a 5% gain over the FX-8150, not great to be honest. I almost believe there is a bottleneck somewhere else in the system that may be playing a role here.

Dishonored:

With Dishonored, it was pretty apparent that the CPU was the bottleneck (even thou we are splitting hairs given the FPS rates we are seeing in this game)

Batman: Arkham City

It was interesting to see virtually no difference between the stock clocked FX CPUs here. It wasn’t until the OC that we saw a noticeable bump to the FPS.

Guildwars 2:

Here we see a nice trending bump to FPS with each configuration. Nice tangible gains are achieved that take us from sub-optimal to “very” acceptable FPS.

Conclusion:

The FX-8350 is closer to what the FX-8150 should have been. There, I said it, and I think that pretty much sums up the comparison…so if you stop reading right now, you at least have the right take away. The CPU performs better in almost all facets, runs more efficiently (processing versus temps versus power usage), and overclocks extremely well (even on air). Investing into a new cooling solution, could yield a really nice return on your investment.

Additionally, where AMD is getting it right again, is with pricing. The FX-8350 specifically will be priced lower than many of “locked” i5 Intel variants, which increases the incentive to pick one up.

Does all of this add up to a must buy? I think the answer will ultimately lie in what you want out of a CPU and the particulars (cost, configuration, usage, and preference). However, I will say that AMD has positioned themselves much better this go around and there are more reasons to buy an FX-8350 then there was an FX-8150. I applaud AMD for the hard work they have put into giving the FX-series some of the love it was missing.  However, the FX-Series is still not the FX series of old, and users will still have to weigh the decision of going with the new FX-Series versus an Intel solution, as the new FX-series doesn’t make it a no-brainer.

Pro’s:

• Cost Attractive
• Unlocked versus its comparable Intel counterparts
• Great multi-threading performance
• Excellent overclocking capabilities
• AM3+ compatible

Con’s:

• Single-threaded performance still lacking over some Intel solutions
• Doesn’t dominate the competition, leaving it’s value subject to configuration and usage variables

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