Introduction

Last week AMD launched their new AM2 platform, we take a look at what performance difference you can expect at the mid-range side of things, with the help of local computer shop Forcom we compared two AMD 3500+ systems, one based on AM2 one on Socket 939.


We thank Forcom.be for providing the hardware used in this review.

With AM2 AMD has changed the on-die memory controller to support DDR2 instead of DDR1. While DDR2 memory modules were more expensive in the past, the prices have fallen quite a bit and now they carry a comparable price-tag as the DDR modules.

Looking at the prices of the new processors at Forcom.be they are remarkably evenly matched compared to their older socket versions:

	AM2	S939/S754
Sempron 64 3000+	€80	€77.95
Sempron 64 3400+	€102	€99.95
Athlon 64 3200+	€143.99	€149.96
Athlon 64 3500+	€199.02	€199.94
Athlon 64 3800+	€299.01	€292.95
Athlon 64 X2 3800+	€315.01	€299.97
Athlon 64 X2 4200+	€370.01	€372.96
Ahtlon 64 X2 4400+	€485.02	€469.96
Athlon 64 X2 4600+	€574.97	€579.95
Athlon 64 X2 4800+	€654.98	€659.96

So you can build an AM2 system for the same price as an older S939 system, it’s not every day you can buy the latest hardware at the price of the previous generation, so where’s the catch? Time to find out.


Test Setup

Forcom helped us build two similar systems on AM2 and S939 using the 2200Mhz clocked Athlon 64 3500+ CPU. Using this OPN guide we can find out some background info on the CPUs

AMD Athlon 64
ADA3500IAA4CN
LBBVF 0613RPMW
Q504952D60270

AMD Athlon 64 Desktop 2.2Ghz 940pin AM2 vcore 1.35V-1.40V 71°C 512KB L2 Cache – F2 revision (Orleans)

AMD Athlon 64
ADA3500DAA4BW
NBBWE 0607CPAW
Z893416B60364

AMD Athlon 64 Desktop 2.2Ghz 939pin vcore 1.35V-1.40V 71°C 512KB L2 Cache – E6 Revision (Venice)

The 3500+ AM2 version was produced in the 13th week of 2006, which makes it the end of March, Anandtech did their AM2 Performance Preview the 10th of April, so they pretty much had final silicon in their hands by then, they did play around with AM2 back in January but found the performance at that stage to be noticeable worse than S939. So how much have they improved since then, and of course we also got the finished chipset from nVidia to take into account, the nForce5.

Using the hardware at our disposal we build these two systems:

	AM2 Setup	S939 Setup
CPU	AMD Athlon 64 3500+	AMD Athlon 64 3500+
Cooling	Arctic Cooling Freezer 64	Arctic Cooling Freezer 64
Mainboard	Asus M2N32-SLI Deluxe	Asus A8N32-SLI Deluxe
Memory	Twinmos 2*512Mb PC2 4300 DDR2 CL4 4-4-12 2T	Corsair 2*512Mb PC4400 DDR1 CL2.5 4-4-8 2T
Video	Sparkle CALIBRE 7900GT 512MB	Sparkle CALIBRE 7900GT 512MB
Other	Maxtor DiamondMax 9 80Gb SATA Antec TrueControl 550W	Maxtor DiamondMax 9 80Gb SATA A.C. Ryan RyanPower2 450W

Why only PC2 4300 memory and what speed is that anyway? PC2 4300 seems to be a separate “standard”: same memory speed as PC2 4200 but slightly tighter timings.

We tried a set of “OCZ PC2 6400 EL Gold Edition 5-5-5-10” but the AM2 system refused to boot, they worked okay in an Intel system though, so we tried Buffalo PC2 5300 2x1Gb kit, the system started up but unfortunately it didn’t get any further than the memory self-test. Could we have a broken board on our hands? Or does the nForce5 require special DDR2 memory? With the PC2 4200 from Twinmos the Asus board worked as it should.

About 2 weeks ago Enhanced Performance Profiles (EPP) for DDR2 was announced, nVidia also refers to it as SLI memory, they developed this together with Corsair and OCZ also recently pledged their support. May not be a bad idea to look into this when you plan on building an AM2 machine. We have emailed OCZ and they are looking into the incompatibility problem with the PC2 6400 EL Gold.

Wonder what memory was used in those other reviews?

Memory Used in AM2 reviews
HardOCP	4x512MB Corsair PC-8500
TechReport	CorsairTWIN2X2048-6400PRO DDR2
AnandTech	Corsair XMS2 DDR2-800 4-4-4-12 (1GB x 2)
TomsHardware	Corsair CAM2X512A-5400UL (XMS5400 V1.2)
PCModdingMy	Corsair 1GB CM2X512-8500 4-4-4-12-1T DDR2-800
Bjorn3D	1GB kit of Corsair DDR 2 8500
HotHardware	2x512MB Corsair PC-8500
Hexus	2 x 512MiB Corsair XMS2-8500
Planet3DNow	2 x 512 MB Kingston HyperX DDR2 PC 6400
NordicHardware	Corsair XMS2 8500 (2x512MB)
Digit-Life	Corsair CM2X1024-6400
AMDZone	2GB of corsair DDR2 at 800 and 1066MHz
HardwareSecrects	Four Corsair CM2X512-8500 modules
GamePyre	2GB Corsair DDR 2 8500 CL4
Motherboards	Corsair DDR2 PC8500 2GB 2X1GB Sticks
Guru3D	Corsair TWIN2X2048-8500C5 DDR2 Corsair TWIN2X2048-6400C4 DDR2
LostCircuits	2x1GB OCZ PC2-6400 EL Dual Channel Platinum XTC modules
Neoseeker	Corsair PC2-8500 memory
PCPer	Corsair TWIN2X2048-6400C4
PCStats	2x 1024MB Corsair XMS2-8500 DDR-2
Bit-Tech	2x512MB Corsair XMS2-8500 DDR2 memory
T-Break	2 x 512MB Corsair DDR2-800 Memory Modules

Corsair seems to be a popular choice, not in the least because nVidia was providing them with their test boards. SLI-ready memory in action.

Let’s compare lowest prices using Newegg.com, 1Gb sticks (1 module):

PC3200 ~80 CL2.5-4-4

PC2 4200 ~$65 - CL4-4-4

PC2 5300 ~$80 - CL4-4-4

PC2 6400 ~$110 - CL4-4-4

PC2 8500 ~$220 - CL5-5-5

Quite an increase when the ratings go up. Enough talk, time for action let’s start our benchmarks ->

Photoshop Script Benchmark Standoff

Driverheaven made this pretty nifty PhotoShop Benchmark which is basically a collection of actions performed on an image and the time measured for each operation. In this benchmark you’ll notice a nice summary of the whole performance difference affair between S939 and AM2, it’s nothing too noticeable and actually not even worth mentioning. But we need proof before we can make these statements of course.

So introducing the only video comparison of S939 vs AM2 in this review for the Photoshop Benchmark, the detailed numbers can be found in the chart below the movie. 12 different filters are applied, at the end of the movie you see a “score” of the amount of tests “won” by each system configuration.




The largest difference was ~3 seconds in favor of the socket 939 system, not too bad, overall the AM2 is not really trailing.

Overclocking Performance Scaling

Overclocking the AM2 system was hampered by the Twinmos memory, which only reached 525Mhz DDR2 (close to PC5300) at CL4 4-4-12 2T. Without touching the memory divisor options this resulted in an FSB increase from 200Mhz to 215Mhz, CPU speed from 2200Mhz to 2365Mhz. Not too impressive and at 215Mhz FSB the system failed to complete several benchmarks and wasn’t very stable.

To see how the system would scale when overclocked we tested at 200/205/210/215Mhz FSB and did the same on the S939 system. These are the results









With the extra bandwidth from the overclocked DDR2 memory the AM2 system closes on the DDR1 powered setup, do note that the DDR1 timings are quite relaxed at CL2.5-4-4-8.

More DDR2 Performance scaling on the next page ->

DDR2 533 to DDR2 800 Scaling

While we didn’t have any luck getting higher rated DDR2 memory to work on the Asus board, our Chinese friend windwithme jumped in and provides us with some interesting benchmarks which compare the performance increase you’ll see from increasing the memory bandwidth. He used the following system:

windwithme's AM2 Test Setup
CPU	AM2 Althon64 X2 4800+
Mainboard	MSI K9N SLI Platinum
Memory	2*512MB Patriot DDR2 1000
Video	nVidia 6800 Ultra
Other	Seagate 7200.7 80Gb AcBel 550W PSU

The CPU was configured to run at 2000Mhz, and using the motherboard divisors the memory was run at 3 different speeds: PC5300, PC6400 and PC8500. The memory timings were the same for all speeds CL3 3-3-8 1T, PC8500 was also tested at 2T.



The benchmarks:








Those memory bandwidth dependant benchmarks shows quite an increase going from PC5300 to PC8500, 2T timings does impact performance, bringing PC8500 performance almost on par with PC6400.

If you look again at how SuperPi scales in our limited overclocking test



S939 calculation time decreases with 2,2 seconds, the AM2’s score decreases with 3 seconds, as DDR2 bandwidth goes up the AM2 platform catches up, if you look at the SuperPi scores from windwithme you see that going from PC5300 to PC6400 is enough for a 2,2 drop, even higher DDR2 memory speeds don’t bring the same performance increase however, as the Athlon 64 architecture doesn’t make use of this extra bandwidth.

Let’s wrap things up ->

Conclusive Thoughts


Socket AM2 the next best thing?

AMD successfully launched their new AM2 platform, the day the reviews appeared on the web, the product could be bought in stores. Motherboards are also available and there’s even AM2 ready DDR2 memory being sold (SLI-ready) today. Price wise building a S939 system or AM2 will be almost the same, and it some cases the AM2 system will turn out cheaper.

The most important question is: do you want AM2? Do you need it?

At this time it’s hard to recommend AM2, not only because it doesn’t offer any performance advantage over Socket 939, but also because Intel is set to release their Core 2 Duo CPU in the coming weeks, and from early performance numbers it will give the fastest AM2 a run for its money.

With the AM2 platform AMD is preparing themselves for future CPU upgrades, the switch to DDR2 should provide future CPU with more bandwidth than DDR1 can ever offer.

There is an obvious upside to AM2, if you buy one now, you’ll be able to get the slowest (Sempron) and upgrade to the fastest (FX) without having to switch motherboards! AMD introduced S754/S939 after they had great success with socket A, but it was a confusing decision, as people who bought a budget S754 motherboard, were stuck in a limited upgrade path, as the higher end models required a S939 socket. With AM2 AMD goes back to the socket A days, which is a good thing.

If you are an impatient hardware enthusiast and you do want to experience the AM2 experience you can be sure that it will offer you performance on par with current S939 systems, if you buy higher rated DDR2 modules. DDR2 PC6400 will equal budget PC3200 DDR1, while DDR2 PC8500 will bring performance levels on par with high end PC3200 (read CL2 2-2-7 1T timings).

Our recommendation is to sit and wait, find out how the Blue Team will do in the next months and reconsider AM2 near the end of year when AMD is planning on releasing 65nm parts, although the first ones might not be high end parts.

Questions/Comments: forum thread