Phenom, Round Two

Nobody but perhaps an AMD employee could call the original Phenom a success. AMD initially struggled with their TLB (Translation Lookaside Buffer) errors which they solved with a crudely implemented BIOS patch that crippled CPU performance. Following this error, a B3 revision of Phenom was released which culminated in the 2.6GHz Phenom X4 9950. Since the Phenom X4 launch in the winter of 2007 it has been a rough journey for AMD with the only promising product coming out of their camp being their Radeon HD 4800 series graphics cards.

AMD Phenom II X4 940 Review

However, rumors started to surface a few weeks back about the powerhouse that AMD was working up in their labs. With claims of no cold bug, enhanced cache size and performance, and 3GHz launch frequencies, it was not surprising that a few of us were getting antsy. Prior to the Phenom launch we heard very similar yet astounding comments leaking from AMD insiders. So, with a Phenom II X4 940 sitting on my desk, how do these claims stack up?

AMD Phenom II X4 940 Review

First off, there is indeed no cold bug and these things just crave cold temperatures albeit with one caveat that will be discussed later. Second, there is no TLB issue resulting in castrated L3 cache so everything is shipshape with the circuits. And last, those 3GHz launch speeds? Very true, and judging from my sample, AMD should be able to release a 3.2GHz or faster Phenom II soon enough.

AMD Phenom II X4 940 Review

Same Architecture, New Process

With everything looking so bright, the processor is rightly codenamed Deneb, which happens to be the 19th brightest star in the sky. Deneb looks to be a bright spot of light in a product lineup that has otherwise consisted of a lot of doom and gloom lately. Initial Deneb-based processors will launch on AMD's AM2+ platform, feature DDR2 memory controllers, and a 125W TDP. Look out in the near future for the new AM3 platform with Deneb processors featuring hybrid DDR2/DDR3 memory controllers. AMD has been pushing the backwards compatibility of their entire lineup and while that hasn't always been true, Deneb looks to at least hold some promise with AM3 chips working in AM2+ sockets and AM2+ chips being direct replacements for older Phenom and Athlon chips.

AMD Phenom II X4 940 Review

AMD has continued to develop their SOI (Silicon On Insulator) technology with their latest being a 45nm SOI manufacturing process. Judging from initial impressions, they have tweaked the process a bit so that it continues to scale with voltages unlike their 65nm process that often hit voltage scaling walls. Add to this the general improvements you get with a process shrink and Phenom II could potentially reverse the overclocking and power consumption stigma that Phenom had branded across AMD.

Below is a short list of differences between Phenom and Phenom II. Most notable are the launch frequencies, cache increases, and respective price jump. The Phenom II X4 940 I have here is a retail sample sent from AMD so it is retail quality silicon and should result in numbers that anyone can relate to. Unfortunately, I wasn't given a retail heatsink but that doesn't factor much into performance.

AMD Phenom II X4 940 Review

Compatible Boards

For reviews, AMD has indicated only three boards that feature full compatibility with Phenom II. The Gigabyte MA790GP DS4H, MSI DKA790GX Platinum, and Asus M3A78-T have all been given the thumbs up by AMD for full support with Phenom II. I personally was shipped a MA790GP DS4H from Gigabyte which booted with the Phenom II X4 940 albeit as an "unknown AMD x86 Processor". A quick flash to the F3M BIOS and I was booting Windows Vista without any issues.

AMD Phenom II X4 940 Review

It is sort of unknown right now which boards in the future will support Phenom II, but in theory all AM2 and AM2+ boards should work so long as the manufacturers update the BIOS accordingly. Keep in mind though that there may be limited overclocking support especially on less popular boards and older SB600 boards. If you are looking for an AM2+ board that will let you fully utilize your chip, one of the boards above would be a good choice or personally contact your manufacturer of choice to see what their official support will consist of.

Earlier, I mentioned socket AM3 and future CPUs. Socket AM3 processors will feature a hybrid memory controller that will work with DDR2 in AM2 and AM2+ boards and a DDR3 memory controller that will work in AM3 boards. The initial Phenom II X4 920 and 940 though will only support socket AM2+ and DDR2, so keep this in mind. Rumor has it that AM3 processors will launch in February, so if you are looking for the most flexible processor it may be worth your time to wait.

The Test System

Today I'll be using our new Phenom II and Core i7 test systems. Both systems utilized the same graphic card and Nvidia's 180.84 drivers. Windows Vista Ultimate x64 was the operating system of choice with SP1 installed. Benchmark values recorded are the average of three runs with values for gaming tests taken with FRAPS running a 60 second repeated route. The Core i7 machine ran the memory with the SPD values of 9-9-9-24 with 1.5vdimm while the Phenom II machine ran the memory with adjusted SPD values of 4-5-4-14 with 2.25vdimm. SPD values weren't correctly utilized due to the BIOS not permitting 4-4-4-12 timings and I am inquiring about a BIOS with such values available.

AMD Phenom II X4 940 Review

AMD Test Platform

Component

Brand/Model

Live Pricing

Processor

AMD Phenom II X4 940

Motherboard

Gigabyte GA-MA790GP-DS4H

Memory

Corsair 2x1GB PC2-8888 CAS4

Video Card

XFX GTX 260 216SP Black Edition

Hard Drive

Seagate 7200.10 320GB

Cooling

Scythe Ninja RevB

Power Supply

Corsair HX1000

Operating System

Windows Vista Ultimate


AMD Phenom II X4 940 Review

Intel Test Platform

Component

Brand/Model

Live Pricing

Processor

Intel Core i7 920

Motherboard

ECS X58B-A

Memory

G.Skill 3x1GB PC3-12800 CL9

Video Card

XFX GTX 260 216SP Black Edition

Hard Drive

Seagate 7200.10 320GB

Cooling

Intel Core i7 920 Box Cooler

Power Supply

Corsair HX1000

Operating System

Windows Vista Ultimate

Cinebench and POV-Ray

Cinebench and POV-Ray are two applications that render images in very different ways. POV-Ray is a ray tracing program that has the ability to render photo realistic images. Ray tracing is one of the many routes that may be pursued for future graphic cards but at this point processors aren't fast enough to render scenes in real-time. Cinebench on the other hand uses a more standard animation suite called CINEMA 4D from MAXON and provides a "real-world" example of number crunching while providing an easy way to differentiate between different hardware configurations.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

Judging by POV-Ray and Cinebench, Phenom II is slightly slower clock-per-clock compared to Core i7. Having half as many available threads guarantees a loss for Phenom II in SMP applications. With that being said, it looks like a 3.2GHz Phenom II would equal a 2.66GHz Core i7 in single-threaded and weakly-threaded applications.

wPrime and SuperPi

Here I tested sheer computational power with wPrime and Super Pi. These tests are as synthetic as it gets but are quite important to the overclocking community. SuperPi is a single-threaded application that calculates Pi to a certain number of digits while wPrime calculates the square-root of a number and splits the workload amongst all available cores.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

In wPrime it looks like Core i7 struggles with the single-thread results with Phenom scoring decisive victories in the single-threaded instances while Core i7 pulls through in SMP. Super Pi isn't even a contest as it has favored Intel processors since Core Duo.

3DMark Vantage and 2006

3DMark Vantage is the latest 3DMark test from Futuremark. Traditionally, 3DMark focused on GPU performance but with 3DMark 2006 and Vantage, Futuremark has given more attention to the CPU. 3DMark Vantage features two CPU tests that focus on either artificial intelligence calculations or physics calculations. 3DMark 2006 features two CPU physics simulations of differing quality. These tests scale incredibly well with cores so the more threads available the higher the score.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

3DMark Vantage is an interesting application. At stock speeds Phenom II and Core i7 have identical GPU scores, but Core i7 has a massive CPU score. The 500MHz overclock though bumps Phenom II over Core i7 due to the sheer CPU performance boost. 3DMark 2006 shows a solid win for Phenom II at both settings due to the much higher SM2 and SM3 scores with the CPU score not being as significant.

WinRar and Sandra 2009

SiSoft's Sandra has become a mainstay in checking system performance while WinRar is a commonly used archiving tool. With Sandra 2009, I will be testing the memory bandwidth and latency while with WinRar I'll test the system's theoretical compression speed to provide another real-world test.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

The Sandra ALU/FPU tests favor Intel's SMP core, and the latency test favors Intel's fast DDR3 integrated memory controller. Fast memory access used to be AMD's pride and joy but it looks like times have changed until AMD moves to DDR3 with AM3. WinRAR once again repeats what we already know. The single-threaded results, however, are slightly disturbing compared to previous performance differences.

Call of Duty 4 and Farcry 2

Call of Duty 4: Modern Warfare is a first-person shooter developed by Infinity Ward and published by Activision for Xbox 360, Playstation 3 and PC. It is the fourth installment in the Call of Duty video game series. It was announced on April 25, 2007 and was released on November 6, 2007 in North America. Far Cry 2 is a first-person shooter developed by Ubisoft for Xbox 360, Playstation 3 and PC. It was marketed as the true successor of the popular title Far Cry.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

The first gaming test was in Phenom's favor at all resolutions. I'd attribute this mostly to the clockspeed advantage Phenom II has over Core i7.

Crysis and Crysis Warhead

Crysis is a science fiction first-person shooter computer game that was developed by Crytek, and published by Electronic Arts. It was released on November 15, 2007 in the United States. Crysis Warhead is the independent expansion of Crysis and was developed by Crytek, and published by Electronic Arts. It was released on September 12, 2008 in the United States.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

Crysis and Crysis warhead have some strenuous graphics that are more or less graphically bottlenecked at all resolutions. I'd call this a draw, neither processor did exceptionally well.

Assassin's Creed and Fallout 3

Assassin's Creed is a 3rd person stealth game that was developed and produced by Ubisoft. It utilizes the same engine as Prince of Persia albeit with differing filters and textures. Assassin's Creed was released for the PC, Xbox 360, and Playstation 3 on November 17, 2007 in the United States. Fallout 3 is an action role-playing game developed and produced by Bethesda. It was released for the PC, Xbox 360, and Playstation 3 on October 28, 2008 in the United States.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

Assassin's Creed was a solid win for Intel. Fallout 3 was an odd title to test due to the minimal performance losses going from 1280x1024 to 1920x1200. This is mostly a draw with unusual results at 1920x1200 required a re-test which yielded the same results.

Company of Heroes and Supreme Commander

Company of Heroes is a real-time strategy computer game developed by Relic Entertainment that was released on September 14, 2006. On May 29, 2007 Relic released a patch for Company of Heroes that supports DirectX 10 and we used the latest patch to test DirectX 10 game performance. Supreme Commander : Forged Alliance is a stand alone expansion for the real-time strategy game Supreme Commander and was developed by Gas Powered Games. It was released on November 6, 2007 to the United States.

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

Company of Heroes was a marginal win for Intel at low resolutions. Supreme Commander Forged Alliance features one of the hardest time demos I run. It involves 500 marching units along with two nuclear detonations and an ACU detonation resulting in single digit FPS at 1920x1200. Phenom II did well maintaining better minimum frames per second but was considerably more jittery at 1920x1200. On the opposite end it did incredibly well at the "cpu limited" 1280x1024 resolution resulting in a overall win.

Preliminary Overclocking

To be honest, I've barely even scratched the surface of Phenom II in regards to overclocking. I only have one sample and lack any adequate temperature reading software so I've been more or less flying blind. I figured 1.45vCPU was a nice maximum vCORE for 45nm but expect much better overclocks down the road. I did three overclocking tests, maximum HTT with a low multiplier and stock vCORE, maximum frequency with multiplier overclocking and high vCORE, and maximum frequency with HTT overclocking and high vCORE.

Click images to expand

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

AMD Phenom II X4 940 Review

I really was more displeased with myself than the actual processor in overclocking Phenom II. Even after spending hours playing with the processor, I found it very hard to break the 250HTT barrier. Afterward, I realized I was running the memory controller at 2.54GHz with "low" IMC volts which may have been a frequency bottleneck.

Sadly, I cannot comment on the temperatures I was hitting or what it takes to hit 4GHz, yet. Once this article is published, then I'll be a bit more liberal with voltages and really start bashing down clock barriers. I have plans on testing with air heatsinks, dry ice, a cascade, and liquid nitrogen, all the tools in an avid overclocker's arsenal.

Power Consumption and Voltage Scaling

Power consumption was measured at the powersupply with a Kill-a-watt power meter. Idle was the recorded value after booting Windows Vista and giving the system 15 minutes to settle with zero CPU utilization. 100% load was the recorded average of three runs of running wPrime 1024M with 8 threads and two instances of SuperPi 32M to insure 100% CPU utilization. Two thread load was the recorded average of three runs of running wPrime 1024M with 2 threads with the affinity fixed to two cores and a Super Pi 32M instance with affinity fixed to the same two cores.

AMD Phenom II X4 940 Review

I was modestly surprised by the Phenom II power consumption numbers. Phenom was a powerhog but even with the "high" 1.30v CPU the processor's power consumption was surprisingly low. The 100% load for Phenom II was just a hair above the idle voltage for Core i7. It should be noted though that EIST was disabled on the Core i7 system as Cool n' Quiet failed to function on the Phenom II system. However, even with power saving systems in place, Phenom II would still sip power compared to Core i7.

Wrap Up and Conclusion

It is hard to pass a single judgment on Phenom II given the market it will occupy. Core i7, for the most part, will be above Phenom II's price range leaving Intel's Q9550 and E8600 processors as its primary opponents. It is unfortunate that I no longer have a Yorkfield processor but comparing Phenom II against Core i7 showed how strong of a contender it will be.

AMD Phenom II X4 940 Review

For the average consumer, Phenom II is a surprisingly efficient powerhouse and its power consumption numbers will only get better once all the power saving features are enabled in BIOS. It is also a relatively cheap platform, compared to Core i7. An off-the-cuff estimate, I'd say you pay 60% of the price for a Core i7 system and get 80% of the performance. For what I imagine the average consumer desires, streaming video, gaming, light photo editing and encoding, Phenom II will make a sound choice from both performance and price perspectives.

For the enthusiast and amateur overclocker, Phenom II is almost a gift in a black box. With the Black Edition Phenom II X4 940 running ~$300 with shipping, you are getting a very flexible processor that just craves to be tweaked and overclocked. It may have trouble standing up against Core i7 in sheer CPU benchmarks like Cinebench and wPrime, but for 3D applications you just might see a few surprises from Phenom II.

For the rare competitive overclocker, Phenom II brings back fond memories of the Netburst era where frequency was king and finesse was not required in pouring liquid nitrogen. With Phenom II, you can more or less throw whatever cooling you have and it'll keep scaling. Even if Phenom II isn't a able to knock around the Core i7 Extreme Edition, I'd go out on a limb and say it's more fun to overclock.

AMD Phenom II X4 940 Review

If you are looking for a new CPU for an upcoming build, or looking to upgrade from an AMD AM2 or AM2+ platform, the Phenom II AM2+ CPUs may be a very good choice for you. Considering how, in many cases, simply swapping the processor could cut power consumption by a third while increasing performance by 15-25%, it's hard to pass this up. Phenom II will definitely warrant another article exploring its overclocking potential so if you are on the fence about it, maybe that will be able to sway you.

Legit Bottom Line: The AMD Phenom II processor series processor may not be the performance winner in all the benchmarks, but it might not need to be competitive in this day and age when the price tag matters most.