A very smart man once told me that absolute performance doesn’t matter, it’s performance at a given price point that makes a product successful. While AMD hasn’t held the absolute performance crown for several years now, that doesn’t mean the company’s products haven’t been successful.

During the days of the original Phenom, AMD started the trend of offering more cores than Intel at a given price point. Intel had the Core 2 Duo, AMD responded with the triple core Phenom X3. As AMD’s products got more competitive, the more-for-less approach didn’t change. Today AMD will sell you three or four cores for the price of two from Intel.

In some situations, this works to AMD’s benefit. The Athlon II X3 and X4 deliver better performance in highly threaded applications than the Intel alternatives. While Intel has better performance per clock, you can’t argue with more cores/threads for applications that can use them.

When Intel announced its first 6-core desktop processor, the Core i7 980X at $999, we knew a cheaper AMD alternative was coming. Today we get that alternative, this is the Phenom II X6 based on AMD’s new Thuban core:

It’s still a 45nm chip but thanks to architecture and process tweaks, the new Phenom II X6 still fits in the same power envelope as last year’s Phenom II X4 processors: 125W.

Update: AMD tells us that it gave us the wrong pricing on the 1090T. The part sells for $295, not $285, in 1000 unit quantities.

CPU Specification Comparison
Processor Clock Speed Max Turbo L2 Cache L3 Cache TDP Price
AMD Phenom II X6 1090T 3.2GHz 3.6GHz 3MB 6MB 125W $295
AMD Phenom II X6 1055T 2.8GHz 3.3GHz 3MB 6MB 125W $199
AMD Phenom II X4 965 BE 3.4GHz N/A 2MB 6MB 125W/140W $185
AMD Phenom II X4 955 BE 3.2GHz N/A 2MB 6MB 125W $165
AMD Phenom II X4 945 3.0GHz N/A 2MB 6MB 95W $155
AMD Phenom II X4 925 2.8GHz N/A 2MB 6MB 95W $145

You also don’t give up much clock speed. The fastest Phenom II X6 runs at 3.2GHz, just 200MHz shy of the fastest X4.

When Intel added two cores to Nehalem it also increased the L3 cache of the chip by 50%. The Phenom II X6 does no such thing. The 6 cores have to share the same 6MB L3 cache as the quad-core version.


The Phenom II X6 die. Monolithic, hexa-core

There’s also the issue of memory bandwidth. Intel’s Core i7 980X is paired with a triple channel DDR3 memory controller, more than enough for four cores under normal use and enough for a six core beast. In order to maintain backwards compatibility, the Phenom II X6 is still limited to the same dual channel memory controller as its quad-core predecessor.

CPU Specification Comparison
CPU Codename Manufacturing Process Cores Transistor Count Die Size
AMD Phenom II X6 1090T Thuban 45nm 6 904M 346mm2
AMD Phenom II X4 965 Deneb 45nm 4 758M 258mm2
Intel Core i7 980X Gulftown 32nm 6 1.17B 240mm2
Intel Core i7 975 Bloomfield 45nm 4 731M 263mm2
Intel Core i7 870 Lynnfield 45nm 4 774M 296mm2
Intel Core i5 670 Clarkdale 32nm 2 384M 81mm2
AMD Phenom II X4 965 Deneb 45nm 4 758M 258mm2

The limitations are nitpicks in the grand scheme of things. While the 980X retails for $999, AMD’s most expensive 6-core processor will only set you back $285 and you can use them in all existing AM2+ and AM3 motherboards with a BIOS update. You're getting nearly 1 billion transistors for $200 - $300. Like I said earlier, it’s not about absolute performance, but performance at a given price point.

AMD 2010 Roadmap
CPU Clock Speed Max Turbo (<= 3 cores) L3 Cache TDP Release
AMD Phenom II X6 1090T 3.2GHz 3.6GHz 6MB 125W Q2
AMD Phenom II X6 1075T 3.0GHz 3.5GHz 6MB 125W Q3
AMD Phenom II X6 1055T 2.8GHz 3.3GHz 6MB 125W/95W Q2
AMD Phenom II X6 1035T 2.6GHz 3.1GHz 6MB 95W Q2
AMD Phenom II X4 960T 3.0GHz 3.4GHz 6MB 95W Q2

We'll soon see more flavors of the Phenom II X6 as well as a quad-core derivative with 2 of these cores disabled. As a result, motherboard manufacturers are already talking about Phenom II X4 to X6 unlocking tools.

The new Phenom II X6 processors are aimed squarely at Intel’s 45nm Lynnfield CPUs. Both based on a 45nm process, AMD simply offers you more cores for roughly the same price. Instead of a quad-core Core i7 860, AMD will sell you a six-core 1090T. Oh and the T stands for AMD’s Turbo Core technology.

AMD’s Turbo: It Works
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  • kwm - Wednesday, April 28, 2010 - link

    did the big bad caps scare you. sorry Reply
  • Taft12 - Tuesday, April 27, 2010 - link

    OF COURSE 6 CPU CORES WILL PROVIDE A TANGIBLE BENEFIT TO VIRTUALIZED PLATFORMS! Reply
  • Skiprudder - Tuesday, April 27, 2010 - link

    To folks asking for a more detailed overclocking review, I would just say that Anand almost always releases an in-depth OC article on a new CPU architecture anywhere from a day to a week later. I think he usually wants to get the basic info out first, then delve into the nitty gritty for those who OC. Reply
  • silverblue - Tuesday, April 27, 2010 - link

    I think Thuban could've been a little better realised;

    1) Higher uncore speed - whatever happened to the touted 5.2GT/s HT3 link?
    2) Triple channel controller - AMD have been using dual channel controllers for the best part of a decade - this HAS to be starving Thuban
    3) Keeping the Phenom II's core control system. Phenom I may have been more elegant, but even if Thuban is faster at ramping up the voltages, it'll still result in issues with XP and Vista. So, the targetted audience, at least for Microsoft users, would be Windows 7.

    Which reminds me... SysMark is on Vista, an OS known to cause issues with Phenoms. Would this have detrimentally affected the X6's scores, even if two cores are being taxed?

    I don't think extra cache would be viable for AMD. The Athlon II X4s aren't far behind equivalent clocked Phenom II X4s even without any L3 cache, plus the added expense and die complexity would've just pushed prices, and temperatures, upwards. Of course, a higher model with 8MB of L3 cache would be nice to see.

    It's not really a disappointment to see Thuban fail to topple the entry-level Nehalems. Remember that they're logical 8-thread CPUs and are thus more efficient at keeping their pipelines fed. You can still get a high-end AMD setup for cheaper than the competing Intel setups; just throw some heavily threaded software at it and it'll do very nicely. The new X4s may just give Intel cause to drop prices though.

    One final thing - AMD's offerings are known to perform far closer to Intel CPUs when every single bit of eye candy is enabled in games, including AA, and pushing the resolution upwards. It may have been more telling had this been done.
    Reply
  • silverblue - Tuesday, April 27, 2010 - link

    Ignore the last bit; it wouldn't be a good indication of the power of Thuban. Reply
  • gruffi - Wednesday, April 28, 2010 - link

    1) Higher uncore speed means higher power consumption and probably less power efficiency.
    2) You would need a new platform that makes the current one obsolete. You would also need much more time and money to validate.
    3) I actually see no problem.

    Sry, but your claims are unrealistic or pointless.
    Reply
  • silverblue - Thursday, April 29, 2010 - link

    "1) Higher uncore speed means higher power consumption and probably less power efficiency."
    You could just reduce the clock speeds to compensate, assuming a higher uncore yields a satisfactory performance increase. The i7-920 has an uncore speed of 2.13GHz and Phenom IIs at 2GHz.

    "2) You would need a new platform that makes the current one obsolete. You would also need much more time and money to validate."
    Fair dos.

    "3) I actually see no problem."
    The potential for a thread hitting an idle core would still be there as, even with Turbo CORE doing its thing, there would be the potential for three idle cores, however this will be minimised if AMD has decreased the delay needed for a core to ramp back up from 800MHz.

    "Sry, but your claims are unrealistic or pointless."
    That's fine.
    Reply
  • jonup - Tuesday, April 27, 2010 - link

    Nice read; well done Anand! Are you planning to do an OC follow up like you,ve done in the past. Also I noticed that on the second "CPU Specification Comparison" chart on the first page "AMD Phenom II X4 965" is included twice.
    p.s. What's IOMMU? Can someone explain please?
    Reply
  • Ryan Smith - Tuesday, April 27, 2010 - link

    The short answer is that an IOMMU is a memory mapping unit (MMU) for I/O devices (video cards, network controllers, etc). For most readers of this site, the only time they'd use an IOMMU is when using a virtual machine, as an IOMMU allows the virtualize OS to talk more or less directly to the hardware by translating the virtual addresses to the physical addresses the hardware is using. However it does have other uses. Reply
  • jonup - Tuesday, April 27, 2010 - link

    Thanks! Reply

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