Summary: A month after launching Phenom II, today AMD is introducing five new AM3-based Phenom II CPUs. The new processors boast lower price tags and an improved 2.0GHz memory controller. But how do they perform and overclock? Find out in this article!
AMD is trying to ramp their new 45-nm manufacturing process as aggressively as possible, even if that means they have to take a hit on existing 65-nm Phenom processors in the process. Phenom has never been a hot seller for AMD anyway, and all indications are that Phenom II should address this. Already Phenom II has picked up numerous design wins, including Dellís latest XPS 625 gaming PC. AMDís new Phenom II CPUs deliver improved performance over their predecessors, run cooler, and are cheaper for AMD to manufacture. In the end it makes sound business sense for AMD to sweep out the old parts as quickly as possible and bring in the new.
As a result, today AMD is launching five new AM3 processors. All of these chips are priced below $200, making them excellent values for the hardware enthusiast on a budget (and who isnít nowadays). Cheaper CPUs is precisely what we asked for in the conclusion of our Phenom II X4 940 article, so itís great to see AMD respond so quickly.
Despite their new AM3 interface, the processors are backward-compatible with AMDís infrastructure of existing AM2+ motherboards and DDR2 memory. All youíll need to do is update your motherboardís BIOS, and youíll be good to go. In addition, the CPUs are DDR3-ready for Socket AM3 motherboards, with DDR3 memory speeds up to 1333MHz fully supported.
Unfortunately, the new AM3 processors arenít clocked as high as their AM2+ counterparts launched last month, with speeds topping out at just 2.6GHz for quad-core models, but they do correct one minor gripe we had with the AM2-based Phenom II 920 and 940: memory controller and HyperTransport speeds. The integrated memory controller (MC) and HyperTransport (HT) link in the Phenom II 920 and 940 CPUs were limited to speeds of 1.8GHz, whereas previous Phenom 9850 and 9950 CPUs boasted speeds of up to 2.0GHz for the MC and HT link.
AMDís AM3 Phenom II CPUs correct this issue, fully supporting memory controller and HyperTransport speeds of 2.0GHz. In addition, the new AM3 CPUs all boast a TDP of just 95W, making them more energy efficient than their predecessors.
So whatís launching today? Have a look at the following chart:
As you can see, besides introducing a new 910 model number clocked at 2.6GHz, AMD is also launching two new 800-series quad-core parts, the 2.6GHz 810 and the 2.5GHz 805, as well as two new triple-core Phenom II X3 models: the 720 Black Edition and the 710 clocked at 2.8GHz and 2.6GHz respectively. The new 800-series parts ship with less L3 cache than their 900-series counterparts -- 4MB of L3 versus the 6MB L3 found on the 900-series parts, but otherwise theyíre similar.
To see the performance impact of the Phenom II X4 810ís smaller L3 cache, we ran benchmarks of the CPU paired against an underclocked Phenom II 940 as well as the original Phenom 9950. We know, it isnít an exact apples-for-apples comparison since the 940 utilizes a slower HT link and memory controller but itís the closest we could get for testing:
When compared against the underclocked Phenom II 940 running at 2.6GHz, the X4 810 and its smaller L3 cache doesnít lose as much performance as we initially expected. Performance drops less than 1% in Crysis, while Far Cry 2 and World In Conflict ran 3% and 4% slower on the 810ís 4MB L3 cache versus the 6MB 940. Lost Planet showed the biggest drop at 5%.
MP3 encoding with LAME is highly dependant on the CPUís clock speed, so we honestly werenít surprised to see the two Phenom II CPUs pull even in this benchmark. Seeing Cinebench results within the margin of error was a bit of a surprise though, the two processors are practically dead even here too. We did manage to shave 2 seconds off our DivX conversion testing with the 6MB cache found on the underclocked 940 processor, and the Valve particle simulation benchmark also ran 3% faster than the 810.
To test out the performance of their new AM3 processors, AMD sent us two CPUs from todayís launch: the Phenom II X4 810, and the triple-core Phenom II X3 720 Black Edition. The 810 is targeted towards the user who needs four processing cores but doesnít want to pony up the cash for a 910 or 920 CPU, while the X3 720 is obviously positioned towards users who donít necessarily need four cores and want to save even more money.
Physically the new AM3 CPUs look similar to their AM2+ counterparts, although obviously the new AM3 parts have two fewer pins on the underside of the processor. Since AMD hasnít moved to pin-less packaging for their desktop processors just yet, fewer pins is obviously a good thing. The backward compatibility also makes it easier for do-it-yourselfers who picked up a 790GX or 790FX motherboard with AMDís newer SB750 South Bridge last year who wish to upgrade to AMDís latest processors.
Not everyone has an AM2+ motherboard though, or perhaps you want to squeeze every ounce of performance out of your AM3 CPU and wish to upgrade to faster DDR3 memory. For these users, youíll want to upgrade to the latest AM3 motherboard and DDR3-1333 (or better) memory.
So far ASUS, Gigabyte, and MSI have announced AM3 motherboards, with all three manufacturers offering multiple AM3 options. ASUS has announced the most AM3 SKUs to date, with their M4A78 and M4A79 series comprising of four motherboards. The M4A79T Deluxe is AMDís flagship offering and is based on AMDís 790FX+SB750 combo, while the M4A79 Deluxe supports DDR2 memory. For integrated platforms ASUS offers the M4A78 Pro, which is based on AMDís 780G chipset. Finally, the M4A78-E utilizes 790GX.
With AMD baking in enhancements into their new 45-nm manufacturing process, we were eager to see how far we could push our latest Phenom II CPUs utilizing the AM3 socket. With its unlocked clock multiplier and one fewer core, we were particularly curious to see how far we could push the Phenom II X3 720 Black Edition. It didnít disappoint.
We could actually boot up some apps at even higher speeds, but couldnít maintain stability. Windows Vista would BSOD at the splash screen at 4GHz.
We didnít manage to have the same luck with our Phenom II X4 810 sample, but it wasnít due to the fault of the CPU itself, rather weíre chalking it up to a software issue. Unfortunately for whatever reason AMDís Overdrive tool wouldnít allow us to crank up the CPU voltage beyond 1.325V, and when we attempted to dial in higher voltages manually via the BIOS of our motherboard (an ASUS M3A78-T), the motherboard failed to POST. Even if we cranked the HT link speed up just 5MHz with higher voltage. In fact, our Western Digital hard drive would make a clicking noise as if it were about to fail.
So armed with no way to adjust voltage, our X4 810 maxed out at 3.1GHz. Thatís actually a little higher than the speed we hit with the X3 720 at stock volts, and itís also a 500MHz OC, but we canít help but wonder what kind of potential is lying untapped in this particular sample. 3.9GHz perhaps? While it had no problems with the X3 720 BE, the ASUS BIOS is likely having problems picking up the 810.
Besides the AM3 processor and ASUS M3A78-T mobo, we also used Zalmanís all-copper CNPS 9700-Cu CPU cooler along with Antec Formula 5 silver paste, OCZ Platinum RAM and Windows Vista Ultimate 64-bit. Keep in mind that 32-bit operating systems tend to OC further than 64-bit.
Intel Core 2 Quad Q9400
Intel Core 2 Quad Q6600
Intel Core 2 Duo E8400
ASUS P5E3 Premium
4GB (4x1GB) OCZ DDR3 PC3-16000 Platinum
AMD Athlon X2 6000+
AMD Phenom X4 9950 Black Edition
AMD Phenom X3 8750 Black Edition
AMD Phenom II X4 940 Black Edition
AMD Phenom II X4 920
AMD Phenom II X4 810
AMD Phenom II X3 720 Black Edition
ASUS M3A78-T (790GX)
4GB (4x1GB) OCZ DDR2 PC2-8500 Platinum
NVIDIA GeForce GTX 295
500GB Western Digital Caviar SE16
Windows Vista Ultimate 64-bit w/Service Pack 1
Valve Particle Simulation Benchmark
World In Conflict Ė Direct3D
Far Cry 2 Ė Direct3D
Crysis Ė Direct3D
Lost Planet Ė Direct3D
Given the state of todayís economy, everyoneís looking at ways to maximize their money. Whether itís clipping coupons, buying generic, or simply going out less, weíre all finding ways to trim our budgets. In this economy, itís all about affordable goods.
Thatís why the low (sub-$200) pricing of AMDís latest processors is so important. The Phenom II X4 810 is priced at just $175, making it cheaper than Intelís venerable Core 2 Quad Q6600. And thanks to its 2.8GHz clock speed, the Phenom II X3 720 Black Edition performs like AMDís more expensive Phenom II X4 920 in most of the apps we tested.
Only in applications that are specifically designed to stress four or more threads like Lost Planet, Cinebench, Valveís particle simulation benchmark, and our DivX testing did we actually see the 920 outrun the X3 720. And with its unlocked clock multiplier it has tremendous potential for OCíing.
Because of this, of all the processors AMD is launching today, itís the Phenom II X3 720 Black Edition that has us excited the most. For less than $150 you can get a chip that outperforms more expensive quad-core parts in most games, as very few titles are coded to take advantage of more than two threads at a time to this day. Thatís why many enthusiasts have opted to save their money and pick up a Core 2 Duo CPU based on Intelís Woldale core like the E8400 we tested today. The E8400 outperformed the X3 720 in most of the games we tested, but in our media encoding/rendering tests the AMD triple-core CPU won 3/5 benchmarks, and the AMD processor costs about $20 less than the E8400 as well.
The Phenom II X3 720 Black Edition doesnít kill the E8400, but given all this, it makes a very good competitor. Thatís something AMD just couldnít offer for most of last year. The backward compatibility with existing AM2+ motherboards is also great. For maximum bang for the buck, we recommend sticking with DDR2 though, as DDR3 memory prices are still considerably higher than DDR2.
Now weíre just waiting for AMDís first AM3 parts to hit 3.0GHz. Hopefully we wonít have to wait long for this to happen, although online rumors suggest this wonít occur until sometime in Q2í09. Weíll cross our fingers and toes for something shorterÖ
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