Approaching Midyear

Intel's lead remains clear just as much as what steps AMD might take to become profitable again remain a mystery. The layoffs might manage $25 Million a quarter while reducing capital expenditure might be good for another $100 Million but this is a long way from the $500 Million that AMD talked about.

Lately, I've been comparing Intel's and AMD's processors. A couple of things are noticeable. SOI is supposed to confer heat tolerance and AMD's processors now have a very respectable temperature limit of 70 C. Yet, Intel's processors running on bulk silicon now have a top end of 71.5 C. The voltage spread is also noteworthy. AMD's spread ranges from 1.05 to 1.25 volts. Intel's spread is much larger, ranging from 0.85 to 1.3625 volts. Intel's processors seem to run just fine on a much larger voltage spread again on bulk silicon. I also came across a comment in one of IBM's journal articles:

Chips with shorter channels typically run faster but use considerably more power because of higher leakage. In previous-generation processors, these parts would have been discarded because of excessive power dissipation but now are usable by operating at lowered voltages. In addition, chips with longer channels typically run slower, so some of these parts also would not have been used in earlier generation processors because of their low operating frequency, but now they also are made usable by increasing their operating voltages.

This piece was from an article about IBM's Power6 development. However, since this concerns IBM's 65nm process which presumably would be nearly identical to AMD's I have to wonder. I have to say that this reminded me a lot of AMD's initial Barcelona launch. I do wonder if the 2.3Ghz 130 watt chips would have been ones that would have been scrapped in previous generations. To be honest, the current B3 stepping looks a lot more like AMD's planned initial offering. And, with this delay it becomes more doubtful that AMD will hit its target of 2.8Ghz at 95 watts on 65nm. This too presumably would have allowed 3.0Ghz at 130 watts. It now looks like AMD won't get there until 45nm. At least we assume so; there have as yet been no 45nm ES chips reviewed. Hopefully, this won't be like the Barcelona release where AMD snuck the chips out on a Friday to delay review over the weekend. Hopefully 45nm will be something that AMD can finally be proud of.

I know some time ago Ed at Overclockers had suggested that Intel might have had an advantage due to RDR. I had doubted this at the time but have since changed my mind. I realized that Intel had considered their own production marginal without DFM and that AMD has now apparently become serious about using DFM at 45nm and below. It is perhaps possible that Intel's current process advantage at 65nm could be due to just a slight edge gained by making the chip layout easier to produce. If AMD really has made use of DFM at 45nm then the addition of immersion scanning should remove any limits they had at 65nm. This would be fine were it not for the fact that Intel is using high-K at 45nm which is looking more and more like the right choice. It has yet to be shown whether or not AMD can be competitive with low-K.

In fact, it is difficult to imagine how things could be better for Intel than they are right now. Fuad has been suggesting that Intel is having trouble with 45nm production. The only evidence I've seen of this is the lack of 45nm quads at NewEgg. You can find 45nm dual cores from 2.5 to 3.2ghz but quads are still scarce. Of course, even if this is true Intel still has the excellent G0 65nm stepping which is still comfortably ahead of AMD. Considering that AMD won't produce any significant volume of 45nm until Q4 this gives Intel a good six months to tweak 45nm production. Even at that, AMD is unlikely to challenge Intel's current top speeds before 2009.

Intel's chips seem to have a fair amount of headroom as well. The dual core chips seem to be able to hit 4.0Ghz without much trouble. The quad cores might also be able to hit this but it looks like they are limited by socket wattage. If socket 775 were rated for 175 watts Intel could hit 3.5Ghz with their quads with room to spare. Of course, they could always follow AMD and introduce triple cores. This would allow a 175 watt quad to fit within the current socket limit. The problem with this idea is that Intel's marketing department already got up on their soapbox and proclaimed AMD's triple cores to be crippled chips. They would look a bit foolish to go back on this now.

Right now of course this isn't a problem because AMD's B3 chips don't have much headroom and the current triple cores are not being released at higher clocks. But, if triple cores were pushing faster than 3.33Ghz in, say, Q1 2009 what would Intel do? They could up the clock on their dual cores or eat crow and release triple cores of their own. Some suggest that Intel is secretly overrating the TDP limits of its 45nm chips. This presumably would mean that Intel would only have to change the labels to fix the problem. I'm not sure this has any truth to it because while the chips will indeed clock higher the quad TDP ratings seem to match the dual core TDP ratings. So, there is no evidence that Intel is derating its chips. Or perhaps I should clarify that by saying that there is no evidence that Intel is derating the quad chips; the duals do indeed seem capable of clocking higher while staying within the socket limits.

Of course, AMD may not be much competition in the near term. AMD might need high-K to actually pose any threat and by that time Intel will be close to or already producing 32nm. Then again, perhaps Nehalem is much better than has been suggested. I'm a bit divided about the direction that Intel has gone with Nehalem. The IMC is a great idea as is QP. And, putting the loop buffer after the decoding stage does seem like an improvement and probably a lot better than the trace cache on P4. I had been wondering how Intel was going to make SMT work without the old trace cache and this seems to be the answer. But, I still have doubts. The IMC is good but in terms of the benchmarks it seems like a lot of this will be traded off with less use of prefetching with the smaller cache. In terms of real performance this is an improvement but I wonder how it will be on the artificial benchmarks that Intel has been so fond of. Secondly, SMT seems to be one of those ideas that looks great on paper but not in practice. Most likely this was added to give Intel some greater hitting power versus Sun's strongly threaded Niagara. And, it probably will.

The problem is that as a programmer you can't really program for SMT. If you only have one application running then this can work. However, as soon as you run other applications the processor state changes and you can find yourself running slower with SMT instead of faster due to things like sharing buffers, cache, and branch prediction. And, these days with virtualiztion moving up it becomes more and more likely that servers will be running not just multiple applications but multiple OS's as well. This simply cannot be optimized at compile time. Without some method of changing the SMT profile at runtime I can't see how this would work. It seems more likely that SMT will end being an option that most server managers leave turned off. Curiously, AMD seems to be one who is moving towards dynamic load profiling but it has never given any indication that it is interested in SMT. Intel has a tough path to follow trying to make Xeon competitive with Opteron but not so good that it kills Itanium. Once Xeon has 256 bit SSE Itanium will be holding on by only an artificial RAS differentiation. But RAS will undoubtedly become more and more robust in x86 server processors. As bad as Nehalem might be for Itanium it is most certainly what Intel needs for Xeon. I'm eager to see the benchmarks to find out if it is good for the desktop as well.

AMD's Asset Smart Explained

Although Hector Ruiz mentioned the term Asset Smart at the Q1 2008 Earnings Report he avoided explaining what it meant. There has been a lot of speculation in this vacuum but all of it that I have seen has been wrong. Most theories seem to focus on either the idea of selling all or part of a FAB to raise cash or on the idea of making graphic products at Dresden. It is actually something quite different.

Asset Smart deals with manufacturing. Starting from 1998 you have:

1998 - SPC
2000 - APC
2003 - APM
2005 - LEAN
2008 - SMART

The term Asset Light referred to AMD's changes within the Lean project (although some of these had actually started back with the APM project). The next project is SMART. Asset Smart simply refers to similar changes within the Smart project which begins in Q3 2008. Mostly, these projects deal with the process of making chips and trying to reduce manufacturing costs. The groundwork for this next phase was actually begun by AMD back in June of 2007 during SEMICON West when it hosted meetings of the Next Generation Factory (NGF) group. This continued during ISMI in October 2007 and later at SEMICON Japan. For example Semiconductor International covers the Austin meeting here:

In an effort to place a more intense focus on 300 mm fab productivity improvements, Advanced Micro Devices Inc. (AMD, Sunnyvale, Calif.) is hosting ~75 people at its Austin campus today for the second in a series of Next Generation Factory (NGF) meetings.

The day-long Austin meeting will include particpants from six integrated device manufacturers — AMD, Freescale Semiconductor, IBM, Qimonda, Renesas Technologies and Spansion — and 16 semiconductor equipment vendors, said Gerald Goff, senior member of AMD’s technical staff. Six academic experts in fab productivity were also expected to attend, Goff said prior to the meeting.

“The suppliers and IDMs used to work more directly together on productivity issues,” Goff said, adding that the NGF group is intended to complement efforts within SEMI and the International Sematech Manufacturing Initiative (ISMI). “ISMI is not moving fast enough. We have to push this 300 mm fab efficiency issue harder as an industry,” Goff said, adding that ISMI project manager Denis Fandel will be among the attendees at today’s event. “In no way do we want the takeaway from this to be that we are against ISMI,” he said, adding, however, that the growing industry emphasis on 450 mm wafers is “concerning to us.”

Goff said that because AMD was “relatively late getting to 300 mm wafers,” it may have more interest in productivity gains at the 300 mm wafer size than its competitor, Intel Corp. (Santa Clara, Calif.), which seeks momentum behind the transition to 450 mm wafers in ~2012.

You can get more information about this directly from AMD by looking at Doug Grose's Keynote Presentation at the 4th ISMI Symposium.

Back in 1998 AMD was at 2.5 days per mask layer. After SPC, APC, and APM, FAB 30 was down to 1.5 days per mask layer. With Lean, by the time FAB 30 shut down in mid 2007 it was down to just 1 day per mask layer. What AMD wants to do is reduce cost by reducing cycle time just as it has been doing for the past 10 years. As a result of Lean, wafer starts per week have jumped 31%, while labor productivity (monthly activities per operator) has climbed 72%. Monthly wafer costs have dropped 26%, and the already mentioned cycle time per mask layer has been trimmed 23%. However, FAB 36 is still at 1.4 days per mask layer. AMD is hoping to reduce this down to 0.7 days per mask layer (a 50% reduction) by shifting to small lot manufacturing.

The basic strategy involves replacing batch tooling with single wafer tooling and reducing batch size. AMD wants to drop below the current batch size of 25 wafers. AMD figures that this will dramatically reduce Queue Time between process steps as well as reduce the actual raw process time. Overall AMD figures a 76% reduction in cycle time is possible so a 50% reduction should be reasonable. Today, running off a batch of 25 wafers is perhaps 6,000 dies. Reducing batch size would allow AMD to catch problems sooner and allow much easier manufacturing of smaller volume chips like server chips. Faster cycle time means more chips with the same tooling. It also means a smaller inventory because orders can be filled faster and smaller batches mean that AMD can make its supply chain leaner. All of these things reduce cost and this is exactly how AMD plans to get its financial house in order.

Updates And Old Patterns

Amid AMD's torrent of bad news: the exit of Phil Hester, the reduced estimates for Q1 Earnings, and the announced 10% layoffs we can at least give AMD a small amount of praise for getting the B3 stepping out the door. It's a small step on a long road.

We can finally settle the question of whether AMD's 65nm process is broken. AMD's fastest 65 watt, 90nm K8 runs 2.6Ghz while the fastest 65 watt, 65nm K8 runs 2.7Ghz. So, the 65nm process is at least a little better than the old 90nm process. People still keep clamoring for Ruiz to step down. Frankly, I doubt Ruiz had any direct involvement with K10's design or development so I'm not sure what this would accomplish. I think a better strategy would be for AMD to get the 2.6Ghz 9950 out the door as soon as possible and try hard to deliver at least a 2.6Ghz Shanghai in Q3. Since Shanghai has slightly higher IPC a 2.6Ghz model should be as fast or faster than a 2.7Ghz Barcelona. I would say that AMD needs at least that this year although this would leave Intel with the top three slots.

AMD's current strategy seems to recognize that they are not competitive at the top and won't get there soon. The collection of quads without L3 cache, Tri-core processors, and the current crop of low priced quads including the 9850 Black Edition all point to a low end strategy. This is the same pattern AMD fell into back in 2002 when it devalued its K7 processors. Of course in 2002 AMD didn't have competitive mobile and its only server processors were Athlon MP. So perhaps Puma and a genuine volume of B3 Opterons will help. AMD's excellent 7xx series chipset should help as well but apparently not enough to get back into profitability without layoffs.

The faster B3 steppings are an improvement but you get the feeling they should have been here last year. You get a similar feeling when Intel talks about the next Itanium release. Although Itanium began with hope as a new generation architecture its perpetual delays keep that feeling well suppressed. And, one has to wonder how much of Itanium will be left standing when Intel implements AVX in 2010. We all know that HP is the only thing holding up Itanium at this point. Any reduction in support by HP will be the end of Itanium. And, we get a similar feeling about Intel's 4-way offerings which always seem to lag nearly a year behind everything else. For example, although Nehalem will be released in late 2008 the 4-way version of Nehalem won't come out until late 2009. Some still speculate that this difference is purely artificial and Intel's way of giving Itanium some breathing room.

However, as bad as AVX might be for Itanium it has to be a double shock for AMD coming not long after the announcement of SSE5. AVX seeks to copy SSE5's 3 and 4 operand instructions while bumping the data width all the way up to 256 bits. It looks like AMD only has two choices at this point. They can either drop SSE5 and adopt both SSE4 and AVX or they can continue with SSE5 and try to extend with GPU instructions. Following AVX would be safer but would put AMD behind since it is unlikely at this point that they could optimize Bulldozer for AVX. Sticking with SSE5 and adding GPU extensions would be a braver move but could work out better if AMD has its Fusion ducks in a row. Either way, Intel's decision is likely to fuel speculation that Larrabee's architecture isn't strong enough for its own Fusion type design. Really though it is tough to say at this point since stream type processing is just beginning to take off. However, GPU processing does demonstrate sheer brute power on Folding @ Home protein sampling. This makes one wonder why OC'ers in particular cling to the use of SuperPi which is based on quaint but outdated x87 instructions as a comparative benchmark.

There is also the question of where memory is headed. Intel is already running into this limitation with Nehalem where only the server and top end chips will get three memory channels. I'm sure Intel had intended that the mid desktop would get three as well, but without FBDIMM three channels would make the motherboards too expensive. This really doesn't leave Intel anywhere to go to get more bandwidth. Supposedly, AMD will begin shifting to G3MX which should easily it to match three or even four channels. However, it isn't clear at this point if AMD intends G3MX on the desktop or just the servers and high end like Intel. With extra speed from DDR3 this shift probably doesn't have to happen in 2009 but something like this seems inevitable by 2010.