The Top Developments Of 2007
It looks like both AMD and Intel have been as forthcoming as they are likely to be for awhile about their long range plans. The most significant items however have little to do with clock speeds or process size.
The two most significant developments have without doubt been SSE5 and motherboard buffered DIMM access. AMD has already announced its plan to handle motherboard buffered DIMMs with G3MX. This is significant because it means the end of registered DIMMS for AMD. With G3MX, AMD can use the fastest available desktop DIMMs with its server products. This is great for AMD and server vendors because desktop DIMMs tend to be both faster and cheaper than register DIMMs. This is also good news for DIMM makers because it would relieve them making registered DIMMs for a small market segment and allow them to concentrate on the desktop products. Intel may have the same thing in mind for Nehalem. There have been hints by Intel but nothing firm. I suppose Intel has reason to keep this secret since this would also mean the end of FBIMM in Intel's longterm plans. If Intel is too open about this it could make customers think twice about buying Intel's current server products which all use FBDIMM. So, whether this is the case with Nehalem or perhaps not until later it is clear that both FBDIMM and registered DIMMs are on their way out. This will be a fundamental boost to servers since their average DIMM speed will increase. However, this could also be a boost to desktops since adding the server volume to desktop DIMMs should make them cheaper to develop. This also avoids splitting the engineering resources at memory manufacturers so we could see better desktop memory as well.
SSE5 is also remarkable. Some have been comparing this with SSE4 but this is a mistake. SSE4 is just another SSE upgrade like SSE2 and SSE3. However, SSE5 is an actual extension to the x86 ISA. If AMD had been thinking clearer they might have called it AMD64-2. A good indication of how serious AMD is about SSE5 is that they will drop 3DNow support in Bulldozer. This clears away some bit codes that can be used for other things (like perhaps matching SSE4). Intel has already stated that they would not support it. On the other hand, Intel's statement means very little. We know that Intel executives openly lied about their intentions to support AMD64 right up until they did. And, Intel has every reason to lie about SSE5. The 3-way instructions can easily steal Itanium's thunder and Intel is still hoping (and praying) that Itanium will not get gobbled up by x86. Intel is also stuck in terms of competitiveness because it is too late to add SSE5 to Nehalem. This means that Intel would have to try to include it in the 32nm shrink which is difficult without making core changes. This could easily mean that Intel is behind in SSE5 until 2010. So, it wouldn't help Intel to announce support until it has to since supporting SSE5 now would only encourage development for an ISA extension that it will be behind in. Intel is taking the somewhat deceptive approach of working on a solution quietly while claiming not to be. Intel can hope that SSE5 won't become popular enough that it has to support it. However, if it does then Intel can always claim to be giving in to popular demand. It's dishonest but it is understandable for a company that has been painted into a corner.
AMD understands about being painted into a corner. Intel has had the advantage with MCM quad cores since separate dies mean both higher yields and higher clock speeds. For example, on a monolithic quad die you can only bin as high as the slowest core. However, Intel can pick and choose individual dies to put the highest binning ones together. Also, Intel can always pawn off a dual core die with a bad core as a lowly Conroe-L but it would be a much bigger loss for AMD to sell a quad die as a dual core. AMD's creative solution was the Triple Core announcement. This means that any quads with a bad core will be sold as X3's instead of X4's. This does make AMD's ASP look a bit better. I doubt Intel will follow suit on this but then it doesn't have to. For AMD, having an X4 knocked down to an X2 is a big loss but for Intel it just means having a Conroe knocked down to Conroe-L which is not so big. Simply put, AMD needs triple cores but Intel doesn't. On the other hand, just as AMD was forced to release a faster FX chip on the older 90nm process so too it seems Intel has been forced to deliver Tigerton not with the shiny new Penryn core but with the older Clovetown core. Tigerton is basically just Clovertown on a quad FSB chipset. This does suggest at least a bit of desperation since after working on this chipset for over a year Intel will be lucky if it breaks even on sales. To understand what a stumble Tigerton is you only have to consider the tortured upgrade path. In 2006 and most of 2007 Intel's 4-way platform meant Tulsa. Now we get Tigerton which uses the completely incompatible Caneland chipset. No upgrades from Tulsa. And, for anyone who buys a Tigerton system, oops, no upgrade to Nehalem either. In constrast, 4-way Opteron systems should be upgradable to 4-way Barcelona with just a BIOS update. And, if attractive, these should be upgradable to Shanghai as well. After Nehalem though, things become more even as AMD introduces Bulldozer on an incompatible platform. 2009 will without doubt be the year of new sockets.
For the first time in quite awhile we see Intel hitting its limits. Intel's 3.33Ghz demo had created the expectation of cool running 3.33Ghz desktop chips with 1600Mhz FSBs. It now appears that Intel will only release a single 45nm desktop chip in 2007 and it will only be clocked at 3.0Ghz. The chip only has a 1333Mhz FSB and draws a whopping 130 Watts. Thus we clearly see Intel's straining to deliver something faster much as AMD did recently with its 3.2Ghz FX. However, Intel is not straining because of AMD's 3.2Ghz FX chip (which clearly is no competition). Intel is straining because of AMD's server volume share. In the past year, AMD's sever volume has dropped from about 25% to only 13%. Now with Barcelona, AMD stands to start taking share back. There really isn't much Intel can do to prevent this now that Barcelona is finally out. But any sever chip share that is lost is a double blow because server chips are worth about three times as much as desktop chips. This means that any losses will hurt Intel's ASP and boost AMD's by much more than a similar change in desktop volume would. So, Intel is taking its best and brightest 45nm Penryn chips and allocating them all to the server market to try to hold the line against Barcelona. Of the 12% that Intel has gained it is almost certain to lose half back to AMD in the next quarter or two, but if it digs in, then it might hold onto the other half. This means that the desktop gets the short end of the stick in Q1 2008. However, by Q2 2008, Intel should be producing enough 45m chips to pay attention to the desktop again. I have to admit that this is worse than I was expecting since I assumed Intel could do a 3.33Ghz desktop chip by Q1. But now it looks like 3.33Ghz will have to wait until Q2.
AMD is still a bit of a wild card. It doesn't appear that they will have anything faster than 2.5Ghz in Q4 but 3.0Ghz might be doable by Q1. Certainly, AMD's demo would suggest a 3.0Ghz in Q1 but as we've just seen, demos are not always a good indicator. Intel's announcement that Nehalem has taped out is also a reminder that AMD has made no such announcement for Shanghai. AMD originally claimed mid 2008 for Shanghai and since chips normally appear about 12 months after tapeout we really should be seeing a tapeout announcement very soon if AMD is going to release by Q3 2008. There is little doubt that AMD needs 45nm as soon as possible to match Intel's costs as Penryn ramps up. A delay would seem odd since Shanghai seems to have fewer architecture changes than Penryn. AMD needs a tapeout announcement soon to avoid rumors of problems with its immersion scanning process.