AMD Phenom II X4 955: Finally, A Flagship

The last top-end processor we saw from AMD was launched in January of this year. Running at 3 GHz, it leveraged a brand-new-to-AMD 45nm manufacturing process and a number of notable micro-architecture enhancements, including a larger (and faster) L3 cache, Cool’n’Quiet 3.0 technology, and better branch prediction.

But, as mentioned, the subsequent introduction of Socket AM3 the month after saw a brand new platform flanked by more mainstream CPUs, taking a lot of the shine off of what we assumed would be a faster hardware combination.

At long last, AMD is unveiling a new flagshipto go along with AM3: its Phenom II X4 955 running at 3.2 GHz and equipped with the same 6 MB shared L3 cache.

There's really not much to add that hasn't already been said about the Phenom II family, but to recap, the chip is armed with 64 KB each of L1 data and instruction cache per core, 512 KB of L2 cache per core, and again, that 6 MB shared L3.

An integrated 128-bit DDR2/DDR3 memory controller (running at 2 GHz by default) interfaces with a pair of 64-bit channels. If you're using the X4 955 on an AM2+ motherboard, speeds of up to DDR2-1066 are officially available. If you're using it on an AM3 platform, you can install DDR3-1333, though it should be noted that only one module per channel works at that frequency. And whereas AMD shipped its Phenom II X4 940 with a 1,800 MHz HyperTransport link, the X4 955 accelerates that to 2 GHz--just like the other AM3 processors. 

The chip's nominal voltage range is .875V-1.5V, similar to the Phenom II X4 940, so we won't be surprised if power consumption falls within the previous flagship's ballpark. In fact, this new processor also sports a 125W TDP.

The New Dragon: Pictures, Prices, And Comparisons

I’ve mentioned this before, but there was a time when AMD shunned the platform concept, preferring to focus on processors alone. I was critical of that approach back then and recognized the value of Intel’s CPU, chipset, motherboard, networking, storage, etc. approach, especially in the workplace. System builders favored it, and for good reason given centralized support.

Now AMD is fully on the platform bandwagon and we think the decision is a good one. In fact, the company is thumping its platform drum so hard that it’s difficult to believe it ever wanted anything different. First, it was Spider. Then AMD wanted to talk Dragon. And now the company is fawning over this “Dragon Update.”

Do what you will with the marketing terminology—it all boils down to a hardware combination. Dragon 1.0 consisted of a Phenom II, a Radeon HD 4800-series GPU, and a 7-series chipset. All of those components are still in play.

This update nudges us up 200 MHz with a flagship running at 3.2 GHz. It gives us the option of adopting DDR3 memory and a Socket AM3 interface. It’s available alongside ATI’s new Radeon HD 4890 graphics card. And it includes a new processor-in-box reference cooling solution, which is just a tad smaller than its predecessor.

Do all of those “upgrades” emerge at comparable prices to hardware at the time of AMD’s Dragon launch in January? It’s a close match-up. We originally calculated a processor/motherboard/DDR2 memory package at roughly $450 ($275 for the X4 940, $130 for an inexpensive 790GX motherboard, and $50 for 4 GB of DDR2). Today’s update can be done for roughly the same price. The X4 955 is launching at $245, but the cost savings is consumed by the 4 GB of DDR3.

We just so happen to be using a pricier motherboard in our evaluation here: Asus’ $190 M4A79T Deluxe, based on the 790FX, rather than the 790GX chipset.