In search of...AMD quad-core Opterons

If you call an OEM today to get an AMD quad-core powered system, you're likely to get a pitch for an Intel system or an AMD dual-core chip. Why? Quad-core Opterons, those formerly known as Barcelona chips, are in short supply.

The issue was highlighted in an off topic post in George Ou's EFF missive. In the talkback, a reader noted:

I was ordering a couple high-powered work stations last Friday for a client and they wanted to go with AMD's Barcelona (Quad Core). However, when I talked with the OEM I was told to avoid the Barcelona chip as there is a serious flaw in it and AMD has no current answer for it.

I asked what the flaw was but was told they could not discuss it due to their NDA with AMD.

I spoke to an alternative OEM and was told almost the identical thing. So what do hear on this? Is there a serious flaw? Why isn't AMD telling anyone about it? Why is everyone being so hush hush about it? I mean its got to be pretty serious if the OEMs are saying not to buy it...

What's the deal? AMD spokesman Phil Hughes says quad-core Opterons (all resources) are "only shipping to fulfill existing orders." In other words, if you had Barcelona chips on order, say high-performance computing or white box accounts, before launch AMD is fulfilling those orders.

So let's say you're a customer calling an OEM looking for an Opteron system. The OEM knows AMD can only honor preexisting demand right now. It's the fourth quarter. What do you do? Hint: You sell the customer something else without directly bashing AMD.

Is AMD being secretive about the quad-core production ramp? Not at all. AMD detailed what was going on during its last earnings conference call.

AMD chief operating officer Dirk Meyer said on October 18 that Operton's manufacturing ramp was lagging.

We began shipping our new quad-core AMD Opteron processors in the quarter with customer excitement and demand quite high. While our initial production ramp of quad-core Opterons has been slower than anticipated, we expect quad-core Opteron will be widely available by the middle of this quarter; and, we expect to ship hundreds of thousands of quad-core processors this quarter into the server and desktop segments.

Hughes says that guidance is still on track today. Simply put, OEMs should have quad-core Opterons in the first quarter, but each manufacturer will be different.

What's going on behind the scenes is anyone's guess. But if you take a new design you run into glitches turning it into a processor.

Scott Wasson of The Tech Report has a good account of what's going on behind the scenes. AMD apparently has an "errata" problem. Wasson writes:

Chipmakers refer to chip-level problems as errata. Errata are fairly common in microprocessors, though they vary in nature and severity. This particular erratum first became widely known when AMD attributed the delay of the 2.4GHz version of its Phenom desktop processor to the problem. Not much is known about the specifics of the erratum, but it is related to the translation lookaside buffer (TLB) in the processor's L3 cache. The erratum can cause a system hang with certain software workloads. The issue occurs very rarely, and thus was not caught by AMD's usual qualification testing.

An industry source at a tier-two reseller told The Tech Report that the TLB erratum has led to a "stop ship" order on all Barcelona Opterons. When asked for comment, spokesman Phil Hughes said AMD is shipping Barcelona Opterons now, but only for "specific customer deals." Industry sources have suggested to TR that those deals are high-volume situations involving supercomputing clusters. Such customers may run workloads less likely to be affected by any workarounds for the erratum that reduce L3 cache performance, and those customers could potentially consume hundreds of thousands of CPUs. Our sources indicate, and the current availability picture would seem to confirm, that quad-core Opterons are not shipping to OEMs or the channel more generally.

News of this problem is notable because it confirms that the TLB erratum affects Barcelona server processors as well as Phenom desktop CPUs, and that the problem impacts AMD's quad-core processors at lower clock speeds. AMD's initial public statements about the erratum and the delay of the 2.4GHz Phenom seemed to imply that the issue was closely related to clock frequencies. The Opteron 2300 lineup spans clock speeds from 1.7GHz to 2.0GHz. Those CPUs' north bridge clocks, which determine the frequency of the L3 cache, range from 1.4GHz to 1.8GHz.

Wasson has more details in his story. Until this issue is worked out Opterons will be scarce. Hughes says the problems are being fixed. Bottom line: Opterons will hit OEMs in the first quarter, but your guess on timing is as good as mine.