Last September, AMD announced its intention to bring a triple-core processor to market as a mid-range alternative to its upcoming quad-core Barcelona processor. The company's triple-core launch schedule was subsequently derailed by a TLB erratum in Barcelona's B2 silicon revision, but the launch of Barcelona's B3 revision last month put the plans back on track. So last week, AMD officially unveiled its Phenom X3 triple-core processor, code-named Toliman.
AMD is taking a gamble with Toliman. Without a good way of creating product differentiation via clock frequency—current Phenom X4 processors top out at 2.5GHz—Sunnyvale will have to rely almost entirely on core count as a pricing mechanism. That's a risky approach for several reasons. When AMD launched the first desktop dual-core processors in May, 2005, many desktop and consumer-level applications used some level of multithreading and got a boost from the second core. But the benefit of moving from two to three or four cores is much less clear for the majority of workloads and is much more likely to depend on specific application-level optimizations.
It wasn't supposed to be this way, though. If AMD had managed to keep to the roadmaps it was showing last fall, current Phenom X4's would be topping out in the 2.8GHz-3.0GHz range. A strong, high-frequency quad-core part would've given AMD much more freedom to offer parts based on both core count and frequency. As things stand, however, AMD will have to keep very close watch on X3 pricing and the chip's price/performance ratio in order to ensure that the new triple-core defines its own market without cannibalizing X4 sales.
The Phenom X3 (Toliman) and Phenom X4 (Agena) processors listed below all have model numbers that end in x50, which means they're all based on AMD's latest B3 silicon revision. The X3 and X4 are structurally identical; each independent Phenom core has a dedicated 512K L2 cache, and all the cores on the processor share access to a 2MB L3 cache. The two cores are also the same size at 285mm2. Ultimately, Toliman is just an Agena core with one core disabled. In at least some cases, this is done as a means of isolating one defective core from three good ones. This lets AMD improve yields, and it also let's the company push its Barcelona architecture into lower price points and thereby sell more processors.
The table below gives a general overview of AMD's Phenom product line, and a close look at it provides some useful clues about AMD's product strategy.
| Processor | Cores | Frequency (MHz) | TDP (W) | Price | $ per core |
| Phenom X4 9850 | 4 | 2500 | 125 | $235 | $58.75 |
| Phenom X4 9750 | 4 | 2400 | 125 | $215 | $53.75 |
| Phenom X4 9550 | 4 | 2200 | 95 | $209 | $52.25 |
| Phenom X3 8750 | 3 | 2400 | 95 | $195 | $65.00 |
| Phenom X3 8650 | 3 | 2300 | 95 | $165 | $55 |
| Phenom X3 8450 | 3 | 2100 | 95 | $145 | $48.33 |
AMD's current Agena pricing suggests that the company is pricing Phenom X4 at approximately $55 per core. Core price is in line with clockspeed; the X4 9850 is clocked 13.6 percent faster than the 9550, and costs 12.4 percent more. Phenom X3 prices, on the other hand, show considerable variance. The X3 8650 still matches our $55 per-core average, but the X3 8750 is ~18 percent more expensive, at $65, while the X3 8450 is about 14 percent cheaper.
In order to prove itself a viable part, Toliman must demonstrate that its third core can effectively compensate for both the Core 2 Duo's higher efficiency and its higher clockspeed. This is by no means a sure thing, but it's no exaggeration to say that AMD desperately needs its triple-core products to gain real traction in the market. Intel's price cuts last year forced Athlon 64 X2 prices to well under the $100 mark, and AMD's fastest 65nm part, the Athlon 64 X2 5200+, currently lists at Newegg for just $115. The company has already announced that it plans to lay off 10 percent of its workforce in response to a weaker-than-expected first quarter, but cost-cutting can only take a company so far. To attain profitability, AMD needs a presence in the $125+ processor segment, and it has chosen Toliman to carry that banner. Let's see if the processor is up to the task.
Conclusion
It's hard to put a definitive label on AMD's triple-core Toliman. The Phenom X3 series re-establishes AMD's presence in the $150-$200 price point, and the company's decision to fight Intel's dual cores with three of its own is not without merit. Although incapable of sweeping the E6850 in our multi-threaded test scenarios, the X3 8750 won several benchmarks and came within six percent of its dual-core rival in our Lightwave rendering test.
The fact that the E6850 managed to remain competitive, despite being one core short, highlights the 8750's greatest flaw. At just 2.4GHz, the X3 can't reliably best its competition, while the current 2.5GHz ceiling on Phenom X4 precludes the possibility of higher clockspeeds. AMD will eventually release faster Phenom processors, but the company isn't even talking about the 2.8GHz-3GHz speeds it once featured prominently on its Phenom roadmap. According to its roadmaps from last February, we won't see a 2.6GHz X4 or a >2.4GHz X3 until the third quarter of this year. This isn't necessarily a bad thing, particularly if it means AMD has pulled resources away from Phenom to concentrate on its upcoming 45nm Shanghai, but it constrains the CPU manufacturer's ability to adjust its product mixture in the here-and-now.
If you're interested in a triple-core processor, the X3 8650 is probably the best option on the market at this time. The 8750 may be the fastest of the series, but it's actually the worst value in terms of its cost-per-core—just $20 more buys you the X4 9750 at the same clockspeed.
Taken as a whole, the X3 series should bolster both AMD's product positioning and its bottom line. It's not the product that it could be, but its good enough to help the company along towards 45nm, and right now, that's about the best we're going to see. All reports indicate that Shanghai development is going well, but AMD isn't out of the woods just yet.
The Good
- Re-establishes AMD as a competitor in the $150+ market.
- Strong multi-threaded performance in certain tests compared to dual-core alternatives.
The Bad
- When I said "certain" tests, I meant it—triple-core products are not a guaranteed win over Intel's Core 2 Duo
- Pricing on certain models make them a bad deal.
The Ugly
- X3 products would be far more compelling if Phenom could actually scale.
- Still a stopgap measure; Shanghai is the ultimate example of having one's eggs in a single basket.
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