Better thread scheduling could really help Bulldozer

Subject: Processors | November 1, 2011 - 02:48 PM | Jeremy Hellstrom
Tagged: bulldozer, a8-3850, thread scheduling, amd

Windows and to an extent other OSes are now familiar with Intel's HyperThreading and tend to be able to schedule threads in an optimized manner, but what about the eight 'cores' in the AMD A8-3850?  The Tech Report found a way to test this and the results are conclusive; Windows 7 is not optimized properly for Bulldozer.  The Bulldozer has two cores on each module, easy to see in the picture below.  By playing with the core affinity via the command line you can run benchmarks using specific cores, to test the impact clustering together 4 threads in two modules versus spreading out the threads to one per module.  As it turns out, there is a noticeable difference when you do set the processor to run with one thread in each cluster.

"Is an awareness of the shared nature of AMD's Bulldozer architecture the key to unlocking its performance? We investigate."

Here are some more Processor articles from around the web:

Processors

• AMD FX-8150 Bulldozer on Asus Crosshair V @ The Inquirer
• DIY Guides: How To Install/Remove AMD Socket FM1 CPU and Heatsink @ PCSTATS
• AMD FX-8150 Bulldozer Tested - Windows 8 vs. Windows 7 Performance @ Frostytech
• Mobile CPU Comparison Guide @ TechARP
• CPU Performance Comparison Guide @ TechARP
• Intel Core i7 2700k @ kitguru
• Intel Core i7 2700k Flagship Showdown Review @ eTeknix

Checking A8-3850 overclocking capability 7 times

Subject: Processors | August 30, 2011 - 12:50 PM | Jeremy Hellstrom
Tagged: a8-3850, amd, llano, overclocking, APU

Legit Reviews decide that they really wanted to be able to show the overclocking results you can expect from the AMD A8-3850, so they picked up eight of the chips to test each for overclocking ability.  There have been examples in the past of chips with a wide variety of overclocking limits which was often decided by the chip revision but not in all cases.  The test results show that all but two of the chips hit a stability issue when being pushed beyond 3679.5MHz, so you can take that as the most likely result that your chip will provide.  The two outlying chips will be exceptional, in one case in a bad way which you can see in the full review.

"When AMD released the 'Lynx' desktop platform back in June 2011, our motherboard reviewer ran into some bad luck when overclocking the processor. When you get a new platform setup for the very first time you really don't know what to expect and it does take some time to learn all the quirks and nuances of a new processor and motherboard. We recently ordered in six more processors and then overclocked all seven of them to see what the best one would be for our test system!"

Here are some more Processor articles from around the web:

Processors

• AMD A6-3650, A8-3850 APUs @ iXBT Labs
• Desktop CPU Comparison Guide @ TechARP
• AMD A8 3850 A-series ALU @ Metku.net
• Energy-Efficient Processors from Intel Reviewed: Core i5-2500T, Core i5-2390T, Core i3-2100T and Pentium G620T @ X-bit Labs
• All Core i7 Models @ Hardware Secrets
• The Sandy Bridge Pentium Review: G850, G840, G620 & G620T Tested @ AnandTech
• All Core i5 Models @ Hardware Secrets

Llano on Linux, good but not good enough

Subject: Processors | August 22, 2011 - 12:06 PM | Jeremy Hellstrom
Tagged: amd, linux, llano, a8-3850

Phoronix is still satisfying their curiosity about the performance of Llano under Linux.  To that end they assembled an A8-3850 with Gigabyte's GA-A75M-UD2H motherboard, 2GB of DDR3 memory, and a 60GB OCZ Vertex 2 SSD and installed Ubuntu 11.04 64-bit, GNOME 2.32.1, X.Org Server 1.10.1, and an EXT4 file-system.  To power the system they had a few choices but unfortunately the one they were most interested in, AMD's Open64 4.2.4, failed to compile.  That left them with two versions of GCC and Clang to test in a variety of benchmarks.  There is still some work to do to bring all of the power of Llano to Linux, but for now this will give you a good idea which to use.

"Last week were a set of AMD Fusion A8-3850 Linux benchmarks on Phoronix, but for you this week is a look at the AMD Fusion "Llano" APU performance when trying out a few different compilers. In particular, the latest GCC release and then using the highly promising Clang compiler on LLVM, the Low-Level Virtual Machine."

Here are some more Processor articles from around the web:

Processors

• Quick Sandy Bridge vs. AMD Fusion APU Integrated Graphics Comparison @ PCSTATS
• AMD A6-3650 Llano 2.6GHz Quad Core APU Review @Hi Tech Legion
• CPU Performance Comparison Guide @ TechARP
• Desktop CPU Comparison Guide @ TechARP

Overclocking Llano just makes sense, but the RAM not so much

Subject: General Tech | July 25, 2011 - 03:30 PM | Jeremy Hellstrom
Tagged: llano, ddr3-1866, a8-3850

Most reviewers made a financial decision when pairing RAM to review AMD's new Llano A8-3850 processor.  Most chose 1333MHz DDR3, since when building a low cost PC most users are going to choose the lower cost as opposed to spending half the budget simply on DDR3.  After seeing significant overclocks produced by a variety of testers, The Tech Report thought it would be interesting to see the impact of high speed RAM on the performance of an A8-3850, especially the graphics portion.   As it turns out, the decision to go with lower cost RAM made a lot of sense as the the graphical performance did not benefit from faster RAM.

"Will 1866MHz memory make a big difference to the performance of the AMD A8-3850 APU? How does power consumption look without a discrete GPU involved? We aim to find out."

Here are some more Processor articles from around the web:

Processors

• AMD Llano A8-3850 Review @ t-break
• AMD A8-3850 Fusion GPU Performance Analysis @ techPowerUp
• AMD A6-3650 2.6GHz Llano APU Review @ Legit Reviews
• Intel Core i3-2120 & Core i5-2400 LGA1155 Processors Review @ Hardware Canucks
• Desktop CPU Comparison Guide @ TechARP

Video Perspective: AMD Steady Video Technology on AMD A-Series APUs

Subject: Editorial, Graphics Cards | July 25, 2011 - 02:23 PM | Ryan Shrout
Tagged: amd, APU, llano, steady video, a8-3850, video

In our continuing coverage of the AMD Llano-based A-Series of APUs we have another short video that discusses and evaluates the performance of AMD's Steady Video technology publicly released to the world with the 11.6 driver revision this month.  Steady Video, as we described it in our initial AMD Llano A8-3850 review is:

Using a heterogeneous computing model AMD's driver will have the ability to stabilize "bouncy" video that is usually associated with consumer cameras and unsteady hands.

Basically, AMD is on the war path to show you that your GPU can be used for more than just gaming and video transcoding.  If the APU and heterogeneous computing is to thrive, unique and useful applications of the GPU cores found in Llano, Trinity and beyond must be realized.  Real-time video filtering and stabilization with Steady Video is such an example and is exclusive to AMD GPUs and APUs.

As you can see there are no benchmarks in that video, no numbers we can really quote or reference to tell you "how much" better the corrected videos are compared to the originals.  The examples we gave you there were NOT filtered or selected because they show off the technology better or worse than any others; instead we used it for what AMD said it should be used for - amateur video taken without tripods, etc.  

And since this feature works not only AMD A-Series APUs but also on recent Radeon GPUs, I encourage you all to give it a shot and let us know what you think in our comments here below - do you find the feature useful and effective?  Would you leave the option enabled full time or just turn on when you encounter a particularly bouncy video?

If you haven't seen our previous Video Perspectives focusing on AMD A-Series of APUs, you can catch them here:

• Video Perspective: AMD A-series APU Overclocking and Gaming Performance
• Video Perspective: AMD A-series APU Dual Graphics Technology Performance

Llano cares about your DIMMs, the size, speed and number of them

Subject: Memory | July 19, 2011 - 01:14 PM | Jeremy Hellstrom
Tagged: llano, a8-3850

Legit Reviews did a marathon testing run on Llano to see just how dependant is on the memory subsystem.  They took a variety of 4GB DDR3 DIMMs, at 1333MHz, 1600MHz and 1866MHz, which they tried in pairs as well as with all four memory slots filled.  Their testing shows that 1600MHz really is the sweet spot for Llano, not as expensive as the 1866MHz kits and in some tests noticeably faster than the 1333MHz DIMMs.  Also of note was the consistently better performance with 4 DIMMs as compared to a pair.

"We found that the memory bandwidth ranges from 13GB/s to 16GB/s with typical dual channel memory kits on our AMD A8-3850 APU and Gigabyte A75-UD4H motherboard. This difference doesn't sound that great, but a 3GB/s increase when dealing with 13GB is a very nice 23% performance increase. Most of this performance gain is seen when moving up from a 1333Mhz to a 1600MHz memory kit is where you'll see the largest performance jump. For example 2x4GB 1333MHz CL8 memory kit was able to hit ~12.7GB/s memory bandwidth, but the 2x4GB 1600MHz CL8 memory kit has ~15.0GB/s of memory bandwidth, which is a very nice 18% improvement over 1333MHz..."

Here are some more Memory articles from around the web:

Memory

• G.SKILL RipjawsX F3-14900CL9Q-8GBXL Kit Review - Leading The Charge @ The SSD Review
• Autographed signed Kingston HyperX X2 Grey Series 4GB 1600MHz Memory Kit @ eTeknix
• Patriot Gamer 2 AMD Edition PC3-12800 8GB @ Tweaktown
• Corsair Vengeance LP 1600MHz 8GB Memory Kit Review @ eTeknix
• Kingston HyperX Dual Channel 2133Mhz CL9 Memory Review @ Ninjalane
• Mushkin Ridgeback Redline Enhanced DDR3 @ Benchmark Reviews
• Kingston HyperX X2 Grey Series 4GB 1600MHz Memory Kit Review @ eTeknix
• Crucial Ballistix 8GB DDR3-1600 BL2KIT51264BA160A @ Overclockers Online
• Crucial Ballistix Sport PC3-12800 CL10 12GB Kit Review @ Real World Labs

Overclockers Achieve Impressive Llano Overclocking Results, Come Close to 5GHz

Subject: Processors | July 18, 2011 - 11:15 PM | Tim Verry
Tagged: superpi, overclocking, LN2, llano, APU, amd, a8-3850

In a feat of overclocking prowess, the crew over at Akiba have managed to push the AMD Llano A8-3850 to its limits to achieve a Super PI 32M score of 14 minutes and 17.5 seconds at an impressive 4.75GHz. Using a retail A8-3850 APU, a Gigabyte GA-A75-UD4H motherboard, and a spine chilling amount of Liquid Nitrogen, the Japanese overclocking team came very close to breaking the 5GHz barrier.

Just how close did they come? 4.906.1GHz with a base clock of 169.2MHz to be exact, which is mighty impressive. Unfortunately, the APU had to undergo some sever electroshock therapy at 1.792 Volts! Further, the 4.9GHz clock speed was not stable enough for a valid Super PI 32M result; therefore, the necessity to run the benchmark at 4.75GHz.

The extreme cooling ended up causing issues with the motherboard once the team tried to switch out the A8-3850 for the A6-3650; therefore, they swapped in an Asus F1A75-V PRO motherboard. With the A6-3650, they achieved an overclock of 4.186GHz with a base clock of 161MHz and a voltage of 1.428V. The overclockers stated that they regretted having to swap out the Asus board as they believed the Gigabyte board would have allowed them to overclock the A6-3650 APU higher due to that particular motherboard’s ability to adjust voltage higher.

Although they did not break the 5GHz barrier, they were still able to achieve an impressive 69% overclock on the A8-3850 and a 61% overclock on the A6-3650 APU. For comparison, here are PC Perspective’s not-APU-frying overclocking results. At a default clock speed of 2.9 and 2.6 respectively, the A8-3850 and A6-3650 seem to have a good deal of headroom when it comes to bumping up the CPU performance. If you have a good aftermarket cooler, Llano starts to make a bit more sense as 3.2GHz on air and 3.6GHz on water are within reach.  How do you feel about Llano?

Video Perspective: AMD A-series APU Dual Graphics Technology Performance

Subject: Graphics Cards, Processors | July 13, 2011 - 02:13 PM | Ryan Shrout
Tagged: llano, dual graphics, crossfire, APU, amd, a8-3850, 3850

Last week we posted a short video about the performance of AMD's Llano core A-series of APUs for gaming and the response was so positive that we have decided to continue on with some other short looks at features and technologies with the processor.  For this video we decided to investigate the advantages and performance of the Dual Graphics technology - the AMD APU's ability to combine the performance of a discrete GPU with the Radeon HD 6550D graphics integrated on the A8-3850 APU.

For this test we set our A8-3850 budget gaming rig to the default clock speeds and settings and used an AMD Radeon HD 6570 1GB as our discrete card of choice.  With a price hovering around $70, the HD 6570 would be a modest purchase for a user that wants to add some graphical performance to their low-cost system but doesn't stretch into the market of the enthusiast.

The test parameters were simple: we knew the GPU on the Radeon HD 6570 was a bit better than that of the A8-3850 APU so we compared performance of the discrete graphics card ALONE to the performance of the system when enabling CrossFire, aka Dual Graphics technology.  The results are pretty impressive:

You may notice that these percentages of scaling are higher than those we found in our first article about Llano on launch day.  The reasoning is that we used the Radeon HD 6670 there and found that while compatible by AMD's directives, the HD 6670 is overpowering the HD 6550D GPU on the APU and the performance delta it provides is smaller by comparison.  

So, just as we said with our APU overclocking video, while adding in a discrete card like the HD 6570 won't turn your PC into a $300 graphics card centered gaming machine it will definitely help performance by worthwhile amounts without anyone feeling like they are wasting the silicon on the A8-3850.