Mal’s Computer Corner

Platform: PC

Developer: Advanced Micro Devices and ATI Technologies, Inc.

Nerd Rating: 5 out of 10

Reviewed By Malefico

Update: Read my article here for important, new information on the APU market.

What is a CPU?

A CPU, or Central Processing Unit, is the basis of your gaming system, whether you play console, PC or both.  It is the tiny brain that converts zeros and ones into zombie parts flying through the air.  In very basic terms, what a CPU does is take instructions or data from memory and, pertinent to gaming, use them to do things like position objects and elements of the environment on the screen, account for interactions between objects and change the game world as a result.  The zeros and ones, called binary code, represent off, no, stop (zero) or on, yes, go (one).  The CPU receives this code as pulses of electricity in predetermined micro-voltages, with a low-voltage pulse representing a zero and a (relatively) high-voltage pulse denoting one.  Aside from thousands of tiny wires, or traces soldered onto the CPU die that connect the CPU to the memory, storage and other devices, CPU’s have a Control Unit that directs the action, and one or more Arithmetic Logic Units and Floating Point Units that actually crunch the numbers.  ALU’s perform operations that will result in whole numbers, or logical comparisons.  For instance IF weapon_ammo > 0 THEN fire weapon, ELSE Force Reload.  FPU’s calculate expressions that will result in a decimal result.  Additionally, modern microprocessors typically have levels of memory cache built into the chip, as many as three levels.  As an analogy, if you go to an amusement park you may (will) find yourself in a long, winding line waiting to get on a ride.  At the end of that line, a worker is controlling THE FELT ENCASED BARRICADE, that arbiter of how many guests will be allowed through to get into much smaller lines and finally into the newly vacant ride cars.  In much the same way, level three cache is the largest, holding data and instructions the program will need shortly.  As data and instructions are to be used, they are transferred into level two and then level one cache, then finally into the cars (ALU’s or FPU’s) to speed along their way. There’s quite a bit of complexity as to how quickly and in what fashion application info is processed, but this gives you a basic overview of what’s going on inside your favorite game box’s head as it sits there inscrutably entertaining you.

Various factors influence CPU performance, but the most meaningful are clock rate (or core frequency) and core multiplier (also known as IPC or Instructions Per Cycle).  Clock rate is the measurement of the frequency at which the crystal inside the CPU oscillates.  Core multiplier is the number of instructions that can be processed per clock cycle.  Taking the venerable Athlon II X2 250 (The Thing That Will Not Die) that is in the system I’m writing this on, and the one I use to review games (for why see my profile) as an example, the factory clock rate is 3000MHz, or 3GHz, and it can process a maximum of 15 instructions per cycle. This is woefully slow compared to the newest, fastest processors but it soldiers along just fine for its intended purpose.

What is a GPU?

 A GPU, or Graphics Processing Unit, is a specialized microprocessor that excels in processing and rendering graphics data.  Most GPU’s are present in computer systems in the form of video cards, also called display adapters, discrete GPU’s or discrete video cards.  Drawing objects takes more processing power than just about any other task.  Additionally, to render graphics quickly a processor must be able to receive and execute instructions simultaneously using multiple simple computing units, rather than consecutively.  This is called parallel processing.  So, what it amounts to is that GPU’s are able to spread the processing load out among numerous (some high-end video cards have over 1000) simple processing “cores” so that in aggregate the GPU is able to decode and display images much more rapidly than a CPU, and incorporate nifty lighting and texture effects.  Trying to have a CPU (or a lower-end video card) handle these tasks results in stuttering or freezing of the screen as the hardware tries to handle significant changes in the game environment.  Recently, GPU’s have been used to explore alternate ways of assigning hard-core processing tasks that don’t involve graphics, utilizing the combined power of hundreds of cores by splitting up data and instructions to maximize their effectiveness.

What is an APU?

A number of years ago one of the big two in processors, AMD, bought ATI Technologies, a major player in the GPU industry.  Shorlty thereafter, they announced a program to develop and market what they called an APU, or Accelerated Processing Unit.  I think All-purpose Processing Unit would be more apt, since these chips are nowhere near the top of the heap in terms of raw computing power, but nobody asked me.  At any rate, the goal was to produce a single device that combined the processing power of traditional CPU cores with a small-scale GPU on a single chip.  Today, the concept has gone through three public releases, with each generation of product split into two parts, a high-performance version for desktops and a low-power version for devices like laptops, notebooks and tablets.  There are numerous more detailed articles and reviews on these products that contain much more information than need be present here.  This review will focus on the second generation of APU, commonly called Trinity chips for a couple reasons.  First, the graphics performance of Trinity versus the newest series, called Richland is very close, and by overclocking just the GPU portion of a Trinity chip you can match Richland stock performance at a significantly lower price.  Second, both the XBox One and PS4 are utilizing modified Trinity chips to play the next-gen console games.  In the future, the APU will become more flexible, with multiple cores able to shift priorities independently, on-the-fly from from application to graphics processing and back, resulting in a highly flexible platform for users who don’t need the very best graphics but want to be able to enjoy casual gaming or watching HD movies without scrificing the ability to complete more “serious” tasks, and without spending the extra money that goes along with a discrete video card and the system improvements that have to be made to support the additional power/cooling requirements that go along with a video card.

So how good are integrated graphics?

Integrated graphics is a term used to describe  graphics chipsets that were first part of motherboard architecture but more recently have been moved onto the CPU die itself.  Many CPU’s today support some form of integrated graphics capability, but not of the quality present on APU’s.  From the inception of the modern personal computer, integrated graphics have gone from barely acceptable to quite good.  They’ve had numerous iterations, too many to list here.  And with each advance in technology, they have gotten better, whether noticeably or imperceptibly.  With AMD Apu’s, integrated graphics have received a major upgrade.  If you compare Intel’s best integrated graphics package with the AMD APU capabilities, AMD outperforms Intel by about 100% with the chip we’re looking at, and nearly 200% for the flagship A-10 APU’s.  The difference is great enough that without the benefit of a dedicated GPU, AMD APU’s can play relatively demanding games at acceptable (to me and apparently to most folks who take the APU for what it is) settings, and Intel chips cannot despite the fact that Intel is currently producing the fastest, most-efficient CPU’s available.  Again, it’s not a coincidence that both next-gen consoles are using AMD chips.  And judging from what I’ve seen of games like Battlefield 4, COD: Ghosts and Destiny (The Sickness), the tweaks that were made to the Trinity platform paid off in excellent graphics.

What is Radeon Dual Graphics?

Originally called Hybrid Crossfire, this feature allows a PC user to pair an APU with a compatible Radeon video card to produce results better than either is capable of alone, and better than a traditional CPU paired with the same video card could produce.  At least, that’s the claim.  Compatible Radeon video cards include the HD 6450, 6570 and 6670, although some claim to have achieved better results using more powerful Radeon cards.   Because this build/test utilizes an A8-5500 APU, we’ll be using the XFX Radeon HD 6570 GPU.  These are decent little entry-level video cards, inexpensive and frugal on power, and I recommend them to anyone who wants to add some graphics capability to their system working with a minimal budget.  You can usually find these for between $50-$70, and you can get yourself a decent Power supply and this card for $100.   If you do get one of these, opt for the version that includes 2GB DDR3.  We’ll talk about real world results later in this review.

AND

And before we get to the review…

One last word on graphics.  I’ve never been a gamer that focuses too strongly on graphics.  Sure, I appreciate a nicely rendered environment as much as anyone, but there are so many variables that contribute to the graphics experience I don’t think you can boil it down to resolution and frame rates.  The quality of the art that goes into object models, the quality of animations, the time and attention to detail taken with the game environment, all these things work together to produce an atmosphere that contributes to the overall game experience.  Good graphics are not enough to make a poorly designed game worth playing, and conversely mediocre graphics have never prevented a good game from shining.  To put it simply, it doesn’t matter how good the icing looks if the cake tastes like crap.

The Review

Wow… finally.  It took a while to get here.  I’d like to tell you that I subjected the APU system to a whole battery of benchmarks, but we here at the bacon are just humble game enthusiasts, and we don’t yet have the extensive resources that some other sites do. So, instead I’ll focus on what can be quantified, and give you links to some reliable testing that was done on a very similar system.

The APU system I built very recently was for a client who knew they wanted to go with an AMD system, due to comfort/familiarity with the brand and budgetary constraints; they were attracted by AMD’s claims of graphics performance, especially when paired with a Radeon card to enable the Dual Graphics feature.  This person does some casual gaming, streams video and does some light video editing for school projects and online posts.  Due to the fact that they already had a hard drive, optical drive and Windows license all I had to do was assemble the core components and transplant the drives, simple and easy.  Because there was no cost to the customer for HDD, optical and OS, when I lay out a more traditional budget build later those parts/costs will be omitted.  All costs are current as of 11/7/2013.

So, on to the build:

AMD A8-5500 Trinity 3.2GHz (3.7GHz Turbo) Socket FM2 65W Quad-Core APU, Radeon HD 7560D graphics $98.99
ECS A75F2-A2(1.0) FM2 AMD A75 (Hudson D3) ATX motherboard $69.99
AMD Radeon Performance Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) $89.99
XFX HD-657X-CNF2 Radeon HD 6570 2GB 128-bit DDR3 PCI Express Video Card $66.99
Client hard drive- Western Digital Blue 500GB, Windows 7 Home Premium 64-bit OS already installed
Client Samsung DVD-RW drive
Rosewill FB-03 ATX Mid Tower Computer Case $29.99
CORSAIR CX430 430W ATX12V v2.3 80 PLUS BRONZE Certified Active PFC Power Supply $44.99

Total: $400.94 plus shipping

So, anyone who has built or considered building their own system will immediately notice that I put quite a bit of very fast RAM in this tower.  There are some elemental truths emerging about AMD APU’s and one of them is that these chips like fast memory and lots of it.  If I had my choice, I would have put 16GB into the system, and bumped to 2133MHz RAM.  For an APU DDR3 @ 1600MHz is the bare minimum  Tests have demonstrated that these chips perform better commensurate with the amount of memory they have available to them, and with RAM speeds up to 2133MHz. With RAM faster than 2133MHz performance seems to take a dip and in some cases the systems actually run worse with memory faster than the 2133MHz sticks. An excellent article with testing can be seen here.  That seems counter-intuitive, but may have something to do with deficiency either in the chip design, or possibly a motherboard element that wasn’t fully thought out and is bottlenecking the GPU portion of the APU.  Or, the Trinity chips simply don’t have the legs to utilize anything faster, but that doesn’t explain the performance decrease.

Some other notes.  At the time I built this system, the next chip up in the hierarchy was AMD’s A8-5600K processor.  At the time it was about $20 more, not a huge difference in price, but the customer was not interested in overclocking the chip, and the 5600K offers only a 400MHz increase in base clock speed and has the potential to consume up to 100W of pwer, a substantial 35% more than the 5500.  As a side note, the system as configured, and taking into account the hard and optical drives, should consume no more than about 270W at absolute peak, full throttle use.  So the 430W Corsair PSU is more than adequate and should last the lifetime of the system.  The build itself was straightforward and easy.  Anyone who has installed a CPU will find that there are no surprises with the socket FM2.  The rest of the build was garden-variety fare, and the whole project took less than 90 minutes, including transplanting the drives from the old tower.

There are some extensive benchmarks on similar systems here.  My subjective experience was that the graphics performance was good, though not eye-popping.  The system handled any web games without blinking and didn’t really stumble until I turned up the settings in an FPS.  Even then, it managed 1920 X 1080, AA turned down with acceptable quality and frame rates of 30-45, only dipping below 30 a couple of times very briefly.  Basically, it was what I expected given the hardware, but I couldn’t subjectively perceive any better performance than the builds I assembled using a traditional CPU and the same video card.

So, the graphics performance isn’t bad with this configuration.  The question is, for gaming is it the best you can do for the price?  At $400 for a build that doesn’t take into account the need for storage and an OS, I consider this on the ragged edge of budget-friendly.  So, I set myself a $400 parts limit and went shopping for a more traditional gaming setup.  To make things more fair for the APU combo, I’ll use another low-wattage processor and stick to 8GB of good memory.

Alternate gaming build:

Intel Core i3-3240 Ivy Bridge 3.4GHz LGA 1155 55W Dual-Core Processor Intel HD Graphics 2500 $119.99
ASRock B75M R2.0 LGA 1155 Intel B75 Micro ATX Intel Motherboard $57.99
Patriot Viper 3 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) $65.99
SAPPHIRE Radeon HD 7750 1GB 128-bit GDDR5 PCI Express Video Card $84.99
Rosewill FB-03 ATX Mid Tower Computer Case $29.99
CORSAIR CX430 430W ATX12V v2.3 80 PLUS BRONZE Certified Active PFC Power Supply $44.99

Total: $403.94 plus shipping

Not bad, I stayed within a finsky of my target.  It’s three dollars well-spent considering this build will just walk away from the APU setup as resolution increases, and if the player wants to use some AA in order to improve image quality.  Not only that, but the additional speed and power of the 7750 card will result in smoother overall rendering and more delicate details.  Aside from gaming, the 7750 will handle streaming video and playback/editing with ease.  Incidentally, the Radeon HD 7750 is the most powerful video card you can buy that DOES NOT require a 6-pin power lead off the PSU; it works within the 75W peak that can be delivered through the PCI-E slot.   When you figure in power consumption, this build including the supplied drives should consume almost exactly the same as the APU tower, at 275W full-boogie.  The Intel core-i3 series are excellent little processors that run cool and are very efficient and thrifty with power.  I’ve had ample experience with this combo and with little variation it’s one of my go-to builds for clients who want performance on a budget.  For those diehard AMD fans out there, a good option would be to substitute the parts below:

AMD FX-4300 Vishera 3.8GHz (4.0GHz) Socket AM3+ 95W Quad-Core Desktop Processor  $109.99
ASRock 970 PRO3 R2.0 AM3+ AMD Motherboard $64.99

With those components, you can match exactly the APU build cost of $400.94 and arguably have a more competent motherboard in place.  Power consumption jumps to around 300W max, in line with what you would expect given the 95W TDP rating on the FX-4300.

The Verdict

Although the concept sounds good, and no doubt will some day be able to equal more traditional configurations there is no convincing argument for going with an APU build at this time, in my opinion.  You can spend the same money on a more conventional build that consumes negligibly more power and produces superior statistical and real-world performance.  Additionally, since the APU’s are a relatively new product, there have been driver glitches and issues with the Dual Graphics setup, some of which still exist today.  Finally, some experts have questioned AMD’s claims regarding frame rate performance using Dual Graphics, which is explored more fully in this article.

So, is the news all bad for AMD’s new chips?  Absolutely not.  Obviously, Sony and Microsoft saw potential, and from the look of next gen games they were not wrong.  Also, the APU’s shine in devices which, for the most part lack the space for discrete GPU’s and would suffer from the extra power consumption if they had the room.  The new chips have allowed owners of laptops and tablets to enjoy a quantum leap forward in graphics quality, letting them watch movies and stream video in true HD.  On the relatively rare occasion that I get commissioned to build a Home Theater PC, which requires a compact footprint and near-silent operation I go with an APU every time.  The low power consumption/heat output of the APU’s combined with their superior on-board graphics make them a shoo-in for HTPC builds.  And I have no doubt that as AMD continues to push the envelope in this fascinating segment of chip design that they will be able to offer their customers discrete GPU performance in a power and size-efficient package, even for desktops.

Right now though the day, and the game belongs to the old reliable CPU and separate GPU build.