Summary: Intel is no longer the only game in town if you want a 6-core desktop CPU. The Phenom II X6 1090T packs six cores in a highly overclockable package that sells for less than $300. The CPU also features AMD's Turbo Core technology, which can OC the CPU's cores by up to 400MHz. See how it fares against the similarly-priced CPUs from Intel in today's article!
Take the $100 price point for instance. Here AMD offers two quad-core Athlon II CPUs, the Athlon II X4 620 and the X4 630. Right now Newegg offers the 620 for $98, and the 630 for $99, both with free shipping.
In comparison Intelís cheapest quad-core part is the Core 2 Quad Q8400. This is a CPU thatís 1-year old and is based on an outdated LGA-775 platform thatís been replaced, and sells for $163.
At that same price point AMD offers the Phenom II X4 955 Black Edition. The 955 BE is a 3.2GHz CPU with four cores, 6MB of L3 cache, and will run circles around the Q8400.
Now AMD is taking this same strategy of offering more cores for less and applying it to higher-end six-core computing. Launching today are two 6-core CPUs, the Phenom II X6 1090T, which runs at 3.2GHz and sells for $285, and the Phenom II X6 1055T. The 1055T runs at 2.8GHz and sells for $199. These chips are based on AMDís new ďThubanĒ core.
One aspect youíll obviously note about the new six-core AMD CPUs are their lower clock speeds -- AMDís Phenom II X4 965 Black Edition runs at 3.4GHz -- with six cores built-in, AMD had to turn down the clocks a little to maintain power consumption thatís comparable to the quad-core 965 chip.
This is actually quite an accomplishment on AMDís part, as the new X6 chips are built using the same 45-nm manufacturing process as the X4s. When Intel transitioned from four to six cores with the 980X, they had the benefit of utilizing their smaller 32-nm process. AMD is sampling 32-nm CPUs to some of their customers now, but wonít be in full production until the end of this year, with the first 32-nm CPUs coming out early next year.
AMD has tweaked their 45-nm for Thuban, adding low-k dielectric material to the metal layers of the CPU to help reduce leakage. As a result, both six-core Thuban processors fit within the same 125W TDP as AMDís latest quad-core Phenom II CPUs.
To help overcome Thubanís clock speed deficit, AMD has added one new feature to the CPU to boost its performance in cases where its extra cores arenít being taxed: Turbo Core.
With Turbo Core, Thuban processors can automatically underclock CPU cores that arenít being taxed down to speeds as low as 800MHz, the active cores that are being used can then be bumped up to speeds as high as 500MHz over default.
Thatís the grossly oversimplified answer for how Turbo Core operates in theory. In practice though, it is much more complicated than this. Letís discuss this feature in more detailÖ
Like Intel, AMD obviously realizes that there are cases when all the processing cores inside their latest multi-core CPUs arenít being used. Even today, many software apps are only single or dual-threaded, leaving two core idling in a quad-core CPU, and four cores idling in the case of a six-core Thuban CPU.
To address this issue, AMD offered application profiles in their latest builds of Overdrive that would automatically OC the active processing cores when certain programs were run.
This software-based solution required AMD to constantly update their profile database in Overdrive to properly work, and of course it requires the end user to actually run AMDís Overdrive software at all times.
In other words, itís an inelegant solution to the problem. A hardware-based solution that requires no effort from the end user, yet still delivers comparable results is more desirable. In addition, Turbo Core can help make up for some of the clock speed deficit that Thuban suffers from in comparison to todayís Deneb-based Phenom II X4 processors.
With Turbo Core, Thuban is capable of watching the utilization of the CPUís six cores. If three or more cores arenít currently being used by the app, the CPU can reduce the power state on those cores, and Turbo up the three cores that are being used. The unused cores can be idled down to as low as 800MHz, while the active cores can be OCíed up to 500MHz on certain CPUs.
Notice that we said ďactive cores can be OCíed up to 500MHzĒ, and ďunused cores can be idled down to as low as 800MHzĒ. Itís important to note that these arenít 100% guaranteed conditions. To keep the Thuban CPU within its 125W TDP, the CPU canít always OC the active cores the full 500MHz. In some cases the active cores may just be clocked up 100MHz, or say 300MHz. We also noticed that the inactive cores donít always go down to the full 800MHz clock speed. Sometimes they may be running at 1000MHz. This is a little different than Intelís Turbo feature, which definitely does bump up the clocks the full 100% if certain conditions are met.
Also unlike Intelís Turbo Mode, AMD Turbo Core kicks in only when three or more cores are being used. This means in cases where four cores are being taxed, AMD Turbo Core doesnít do anything. It also doesnít completely shut down the inactive cores like Intel Turbo Mode does. As a result, it isnít as power efficient.
In other words, itís definitely still much less advanced than what Intelís offering with their latest CPUs, but itís definitely an improvement over relying on AMD Overdrive software. Itís an incremental step that will hopefully be improved when AMD launches their next-generation Bulldozer CPUs next year.
All AMD CPUs with Turbo Core technology will be denoted with a ďTĒ after the model number. So today weíre getting the 1090T and the 1055T CPUs, and in the future weíll supposedly see 1075T and 1045T processors if you believe the rumors.
With that discussion out of the way, letís go over the rest of the Thuban CPUís specs:
If you recall our review of Intelís Core i7-980X six-core CPU, youíll remember that it ships with a larger 12MB L3 cache. Intelís engineers increased the size of the L3 to maintain what they believe is the optimal ratio between L3 cache and cores which is 2MB of L3 cache per core (although keep in mind that the L3 cache is shared amongst all six cores, so one core can use as much cache as it needs, including the full 12MB L3 for single-threaded apps). Intel was able to increase the size of the CPUís L3 cache without upping the chipís die size thanks to its smaller 32-nm manufacturing process. Thanks to 32-nm, Intel could add cache without making the chip bigger, and thus it isnít more expensive for Intel to produce (assuming of course Intel is getting equal yields which may or may not be the case).
While AMD wonít confirm it, the rumor mill says that AMD will eventually roll out quad-core Thuban CPUs later this year. These parts will merely have two of their processing cores disabled. Presumably the first CPU will be the Phenom II X4 960T. Rumors have also suggested weíll see a 940T part at some time as well.
While the new Thuban CPUs will run fine in existing socket AM3 790FX motherboards with a BIOS update supporting the new processors, today AMD is also rolling out a new chipset, 890FX.
Again, like the 890GX launch a month ago, the new 890FX chipset isnít a next-generation built from the ground up. Itís an evolutionary rather than revolutionary upgrade over its direct predecessor, with the most significant changes found in the South Bridge of the chipset.
Tweaks have been made to the North Bridge, but many of the key specs remain largely unchanged. PCI Express lanes for instance remains the same at 42, which is enough for 2x16 or 4x8 CrossFire (in comparison 890GX is limited to 2x8).
Like the 890GX chipset, 6x1 PCI Express 2.0 lanes hang off the North Bridge, which can be used by motherboard manufacturers to implement full bandwidth USB 3.0 support. While this isnít as elegant as a native USB 3.0 interface thatís built-in to the chipset, itís better than nothing.
890FX is paired with AMDís SB850 South Bridge. As we mentioned in the 890GX article, it offers more USB support (14 USB 2.0 ports in SB850 versus SB750ís 12), a native Gigabit Ethernet MAC, and two additional x1 PCIe 2.0 lanes. Its most notable feature is its 6Gbps SATA support. SB850 supports up to six 6Gbps SATA drives.
The ASUS Crosshair IV Formula Motherboard
To test the capabilities of the new 890FX chipset, AMD sent us a Crosshair IV Formula motherboard from ASUS. The Crosshair IV Formula is ASUSí newest Republic of Gamers motherboards, and is loaded with features that enthusiasts will appreciate.
The most notable is probably Core Unlocker. Unlike previous tools that relied on AMDís ACC tool to unlock CPU cores, Core Unlocker uses the iROG processor thatís built-in to the motherboard to unlock processing cores that have been deactivated at the factory by AMD. ASUS also says that Core Unlocker can be used to enable L3 cache thatís been disabled by AMD in some Athlon II CPUs.
Crosshair IV Formula also ships with ASUS Turbo Key II.
While we never had any problems with it, some people (and websites) complained that ASUSí TurboV EVO was too complicated. TurboV EVO, in case you didnít know, is the marketing term ASUS developed for their iROG processor used on P55 motherboards. The iROG chip could automatically OC your CPU, doing all the work for you. OCíing could be accomplished via ASUSí TurboV Software, or you could do it from within a setting inside BIOS.
ASUS has made things simpler for the Crosshair IV Formula. All you have to do is press the Turbo Key II button located at the bottom of the motherboard, turn on the board, and walk away. The Turbo Key button will then shine red, the motherboard will power on and find the optimal OC speeds for the CPU, and then boot Windows. In our case, it took the iROG processor about 10 seconds to determine that 3.596GHz (16x224.8) was the optimal speed for our particular Phenom II X6 1090T chip. (BTW, we managed to OC our CPU over 4GHz doing things the old-fashioned way.)
To quote the GEICO commercials, itís literally so easy, a caveman can do it. All you need to do is physically press a button on the motherboard and youíre done. If you donít know how to press a button, you probably have a very hard time turning on your PC each day and wouldnít be reading this website.
To undo it, press the Turbo Key button again and it will go from red to white, letting you know that the CPU is no longer OCíed.
Rebooting your PC wonít affect Turbo Key, the next time your PC boots up, itís still OCíed. Even from a cold boot. Itís simply the easiest way to safely and easily OC your processor that weíve ever seen on a motherboard.
Other Republic of Gamers features like the Go Button, GameFirst networking, SupremeFX X-Fi audio, and ROG Connect carry over to the Crosshair IV. Two USB 3.0 ports are available on the board as well.
Intel Core 2 Duo E8600
Intel Core 2 Quad Q6700
ASUS P5E3 Premium
AMD Athlon II X4 635
AMD Phenom II X4 965 Black Edition
AMD Athlon II X6 1090T Black Edition
ASUS Crosshair IV Formula
Intel Core i7-870
Intel Core i5-750
ASUS P7P55D Deluxe
4GB (2x2GB) OCZ Platinum @ DDR3-1333 Speeds
Intel Core i7-980X Extreme Edition
Intel Core i7-975 Extreme Edition
Intel Core i7-920
6GB (2x3GB) OCZ Reaper HPC @DDR3-1066 Speeds
ATI Radeon 5870
2TB Seagate Barracuda XT
Windows 7 Ultimate 64-bit
Resident Evil 5
Valve Particle Simulation Benchmark
Far Cry 2 Ė Direct3D
Crysis Ė Direct3D
Tom Clancyís HAWX Ė Direct3D
Lost Planet Ė Direct3D
With its extra cores, youíd naturally assume that the Phenom II X6 1090T wouldnít scale as well as Phenom II X4 CPUs Ė especially given that itís based on the same 45-nm manufacturing process. However, we hit a new high with our 1090T sample. Check it:
In comparison, we maxed out at 4066MHz with our 125W Phenom II X4 965. We hit over 100MHz higher than that with Thuban!
Anyone who plans to use the processor for heavy-duty rendering work will really appreciate the new Thuban processors. Our results in Cinebench 11.5 in particular were the most impressive. Scoring 5.69 points, the Phenom II X6 CPU was third only to the Core i7-980X and Core i7-975 EE CPUs in performance. Keep in mind that it costs hundreds of dollars less than the Intel CPUs; you could actually buy three Phenom II X6 1090T CPUs and still have over $100 in your pocket. Or you could build yourself an entire Phenom II X6 1090T system with Radeon 5850 graphics for the price of one Core i7-980X.
This processor is simply a tremendous value if you happen to fall in this category.
Most of our readers are die-hard gamers though and here the results are mixed. In apps that are heavily threaded, the Phenom II X6 1090T obviously shines the most. For an example of this, thereís no better example than Capcomís MT Framework engine used in games like Lost Planet, Devil May Cry, and Resident Evil 5. In Lost Planet the Phenom II X6 1090T ran 9% faster than the Phenom II 965. At the same time however this still wasnít enough performance for the chip to outrun Intelís Core i7-920.
In the other games, the Phenom II X6 1090T was outrun by the Phenom II X4 965. Here its 3.2GHz clock speed was an obvious liability.
AMD has tried to address this issue with Turbo Core, but weíve found that it doesnít consistently hit its peak Turbo Core clock speeds. Using Overdrive to monitor clocks, we noticed that speeds were all over the map, even in the same app. Sometimes the cores on the 1090T would go up to 3.3GHz or even 3.4GHz for some time, then theyíd go back down as the other cores speeds came back up.
We never saw Turbo Core hit 3.6GHz in games, and even in the apps where it would get that high, it was never there for more than a few seconds. Also keep in mind that in apps that have four threads, Turbo Core is inactive.
As always with game tests though, the results at 800x600 with 0xAA arenít very relevant for gamers, as no one plays games that way. Instead most gamers crank up the screen resolution and graphics settings, including turning on AA. In these instances, your performance is entirely dependent on your GPU, not the CPU Ė here the Phenom II X6 1090T runs just as fast as the Core i7-980X.
We didnít note anything game-changing in MP3 encoding, compression, or testing with Valveís particle simulation benchmark (which is multithreaded) for the Phenom II X6 1090T. In these cases it took a backseat in performance to comparably priced Core i CPUs from Intel.
Based on this information, itís harder to recommend the Phenom II X6 1090T to gamers than say the more affordably priced Phenom II X4 955 BE and 965 BE. We have a feeling that the 960T could be more attractive as well depending on pricing.
Itís a shame that Turbo Coreís clocks are so variable. On paper at least it looks extremely attractive. In practice though, the advertised Turbo Core speeds arenít hit consistently enough, and even when they are, it can be for short spurts. Not long enough to dramatically impact performance unfortunately. Hopefully this is something AMD will address with their next-generation CPUs due next year.
The beauty of AMDís Phenom II X6 CPUs are their power consumption. Despite integrating two more cores on the same manufacturing process, we observed lower power consumption for the 1090T than our 125W Phenom II X4 965. Keep in mind that we use Cinebench to test CPU power consumption, so all six cores were being taxed for this test. Overclocking looks extremely solid as well.
This is simply a remarkable achievement thatís a testament to Globalfoundries 45-nm process. Clearly theyíve now got it very well dialed in.
Now we await the arrival of cheaper six-core Phenom II CPUs, as well as the first quad-core Thubans. All of these chips should sport the sweet power consumption of the 1090T, but with lower prices. This could be a killer combo that will be hard for many enthusiasts to pass up.
|© Copyright 2003 FS Media, Inc.|