Interview with Jim Keller

1 : Anonymous2021/05/28 19:38 ID: nn5rxa

There are really some great insights into the turnaround of AMD and ZEN:

The funny thing was, we knew we were kind of at the end of the road - our customers weren’t buying our products, and the stuff on the roadmap wasn’t any good. I didn’t have to convince people very much about that. There were a few people who said ‘you don’t understand Jim, we have an opportunity to make 5%’. But we were off by 2X, and we couldn’t catch up [going down that route]. So I made this chart that summarised that our plan was to ‘fall a little further behind Intel every year until we died’.

With Zen, we were going to catch up in one generation. There were three groups of people - a small group believed it (that Zen would catch Intel in one generation); a medium-sized group of people that thought if it happens, it would be cool; then another group that definitely believed it was impossible. A lot of those people laughed, and some of them kind of soldiered on, despite this belief. There was a lot of cognitive dissonance, but I found all kinds of people that were really enthusiastic.

Mike Clark was the architect of Zen, and I made this list of things we wanted to do [for Zen]. I said to Mike that if we did this it would be great, so why don’t we do it? He said that AMD could do it. My response was to ask why aren't we doing it - he said that everybody else says it would be impossible. I took care of that part. It wasn’t just me, there were lots of people involved in Zen, but it was also about getting people out of the way that were blocking it. It was fun – as I’ve said before, computer design needs to be fun. I try to get people jazzed up about what we’re doing. I did all kinds of crazy stuff to get people out of that kind of desultory hopelessness that they were falling into. 

The part about his role at Intel was also interesting:

My team at Intel was 10,000 people, right, so you spend a lot of time on organization charts and budgets, and all kinds of admin, and then it's easy to find yourself just doing that and saying you’ll hand off leadership for a project to this person or this person and that. But the problem is there's so many things that are cross-functional – I want to know what the fab is doing, how does the PDK work, how does the library work, how does the IP team work, how does the SoC integration work, how does the performance model work, how does the software work. Then you find out that if you can't deep dive into all those pieces, bad things happen.

I recommend reading the whole interview

2 : Anonymous2021/05/28 23:34 ID: gztf44f

Keller joined in mid 2012. At that point AMD had already refreshed bulldozer with piledriver (it hit the laptops that spring and desktops in the fall of 2012) and rumored to be preparing an improved bulldozer core in Steamroller. Few months after his arrival there were the first rumors that Steamroller and all the future big cores of that family were actually cancelled.

AMD was quick to deny the rumor. Next year (2013), this, more or less forgotten core that resembles a very beefed up BD got leaked:

Too elaborate to be fake, it was expected to hit the market at some point. It never did. I have always thought that the most likely scenario was that Semiaccurate 2012 story was, duh, accurate and that AMD possibly just scrapped BD family for desktop and server after Piledriver came out. Jim Keller more or less just verified that theory. That abortive steamroller leak was possibly one of the designs destined to forever trail intel that Keller killed.

ID: gzuvnv3

It'd be funny to imagine when JK entered AMD's design team and saw their Bulldozer roadmap be like tf were you guys smokin'.

ID: gzv9i7g

Nah, that funky roadmap got reevaluated much earlier.

Remember, the serve

Bulldozer roadmaps were toned down even half a year before the JK's arrival. Rory Read was already implementing measures to survive the Bulldozer era when JK was rehired.

ID: gzv8n4f

Dunno about Steamroller but there were LinkedIn profiles hinting the Excavator core being repurposed solely for mobile.

The decision to kill the desktop/servers predated JK.

Back in 2011 AMD roadmaps were a mess. For 2012 for the Piledriver generation, AMD planned 10c Pilederivers - 10c FM2-based Komodo and MCM G2012 20c Terramar. The new platforms would be costly to develop and not competitive.

In a Feb 2012 AMD's presentation there were no mentions about those new platforms or CPUs. They were replaced by a bugfixed revision of the original Bulldozer die (Vishera).

So the decision to effectively kill the desktop/server development was carried in late 2011/early 2012.

That S|A news piece is interesting. It was spot on with the big cores and also with Kaveri - it slipped to 2014 instead of acting as the "2013 APU".

My guess is the big cores were killed as an effect of Rory Read's reevaluations in H2 2011.

ID: gzvu8cp

That early Steamroller v1 die shot brings back so many memories. Hard to believe that was almost a decade ago... I was super deeply-versed into the CPU side of AMD at the time, because it was fascinating to see how they slowly began to fall off after the heralded K8 reign to the point they were then.

I was thinking around 2013 and especially 2014 that the report that the "big core" versions of SR and EX had truth to it, because they didn't push any server or desktop successors for Interlagos/Delhi and thus there were no DIY desktop variants either.

They had a 6-core APU successor to Trinity/Richland that would've been Steamroller based, but there were some vague murmurs saying that they had ran into some sort of issues with it, so it was quietly scrapped and re-tooled into a quad-core design... which wound up schedule-slipping anyway and releasing in 2014 despite an intended 2013 launch window. The Excavator design also got re-tooled at some point which had it miss its originally intended 2014 launch window to launch in 2015.

In the end they made a wise choice in killing those 'big core' variants and focusing on semi-custom in the interim until they could get Zen out.

3 : Anonymous2021/05/29 02:45 ID: gztz6lp

I recommend checking out his podcast with Lex Fridman on YouTube, I believe there are actually 2 of them. Three hours each. They are well layed out in terms of chapters, you don't have to watch the whole thing. Both of them are good.

AMD isn't talked about much but his philosophy behind CPU's and such comes up from time to time. It goes into more depth on his approach to CPU's in general. He's a really interesting and intelligent guy, in all aspects of life.

ID: gzuyn4o

I recommend watching them fully, they are well worth it.

4 : Anonymous2021/05/28 22:46 ID: gzt9z4e

It sounds like the classic case of "playing it safe" and aiming for 5% gains here and there, versus going balls to the wall with a huge risk.

Keller made the right call because it worked out, if it had not, all the naysayers would have said "told you it was impossible!".

ID: gztjs6t

AMD had to take risk though, they were in such a bad position and in dire straits. I'm not sure they would still be here if they hadn't, playing it 'safe' was not safe at all.

ID: gztrg0n

Yeah, playing it safe would have doomed AMD so it was all or nothing at that point.

ID: gzurqkc

It really was a perfect storm of AMD starting to execute well and Intel slowing down (mainly due to fab problems tbh). Today, we are all better for it, and I guess we will have it even better once Intel's gears start running again.

ID: gzu05mi

What's most amazing is that AMD has this fire under their butts now and aren't aiming for small generational improvements at all - they're aiming at ~10% each gen AND BEATING IT.

Zen 4 should have about 65~70% higher IPC than Zen 1... and that's just mind-blowing.

ID: gzutncv

And if it had failed, AMD would have gone down the toilet anyway. So I'm not sure there was anything else to do.

5 : Anonymous2021/05/28 22:29 ID: gzt82pk

weirdest part is AMD cockblocking their engineers when their bulldozer design was so vastly different from K10. like you already signed off on a design that made similar mistakes as the failed netburst architecture from intel, why would you tell engineers trying to go back to shorter pipeline, full core designs that it was impossible? hiring MBAs with no knowledge about the business they're managing has to be one of the worst things about corporate culture and also seems to be the reason intel fell behind.

ID: gztb1o2

From what he's sayin they sound like other engineers who were invested in bulldozer uarch that wanted to continue down that way for single digit performance gains each gen

Those dudes probably ain't at amd anymore. Keller joined amd with lisa su in 2012 and 2 years after that lisa su became the ceo and she did a major restructuring

ID: gzthhz6

The just go for the sure thing 5% part is telling. AMD had gotten trapped in the same "stay the course" and don't try for big leaps whenever possible that Intel more recently ran into. In some ways you can blame the way we judge company value and success by the rather disconnected sentiments of wallstreet thinking which is risk adverse and will always push for sure things like a guaranteed 5% verse taking unsure big leaps. The type of thinking that locks you into incrementalism on the engineering side and just increasing marketing expenditure even though it's obvious you are setting yourself up for a slow painful decline. Ofc most engineers have ideas they would love to try but it involves social capital to sell taking those risks, making those bets, and if anything goes wrong in execution it can mean getting thrown under the bus when timelines don't play out as predicted.

Start ups with unlimited venture capital money getting pumped into them can get away with smoke and mirrors marketing bullcrap of products that really aren't bold leaps forward but just filling a new niche. Established institutions at the core of an industry are at the point in a companies development where they have to be steadily providing new value propositions to customers, taking the lead with other established players in the industry, and each generation actually delivering on innovation and value to move the entire industry steadily forward.

ID: gzu5lrw

From what he's sayin they sound like other engineers who were invested in bulldozer uarch that wanted to continue down that way for single digit performance gains each gen

You kinda only able to do that if only AMD have market share dominance, if not that is a disaster.

Right now we have stuck on Ryzen 7 being 8 core only. I help AMD rise it further other than just IPC.

ID: gzvb66k

All the major restructuring happened with Rory Reid, he cleared the path for Lisa.

ID: gztdur2

The CEOs that chose the bulldozer way were engineers (Ruiz/Meyer). The CEO that put the team that created Zen together, was chosen for his business background (Read).

ID: gzth3mr

Keller wasn't back at AMD until after Rory Read took over, so he was quite literally talking about the management under Rory Read at the time. Interestingly Lisa Su was also SVP and general manager at AMD during the time period where management would've been telling Clark that zen was impossible. People like to give all the credit to CEOs but from Keller's responses it seems like things would be much worse for AMD right now if their engineers hadn't stepped up and risked their necks.

ID: gzvbbi1

Hector wasn't CEO of AMD at the time of bulldozer, Hector's bulldozer was different than the bulldozer that ended up being released. The CMT bulldozer that was released was entirely born from Dirk. Remember they scrapped bulldozers in a show framework a couple of different times during that time period. Hector had nothing to do with bulldozer that was eventually released.

ID: gzunl0y

Sounds like this is exactly what happened to him at Intel when he went there. There was one interview where he sounded quite salty about his superior while he was there.

ID: gzutxwr

His superior at intel was the CEO…

ID: gzva4uw

Bulldozer design has been in development for like... 7 years or so. It was plagued with bad decisions. The end result was obviously bad.

ID: gzvdbga

Well it went through three different iterations, what was designed under Hector was scrapped by Meyers for what was eventually released.

6 : Anonymous2021/05/29 05:28 ID: gzue7us

It sounds like Jim Keller saying to the rest of AMD "yeah you can do this" when some of the others were saying they could do it but the company doesn't believe in it is what pushed them to actually go forward with it.

7 : Anonymous2021/05/28 20:32 ID: gzsu0zs

Interesting, thanks. The Meta tag is to talk about the subreddit itself though.

ID: gzsy03x

ok thx. changed it to "discussion"

8 : Anonymous2021/05/29 12:58 ID: gzv8ani

Yeah it's because around this time is when they did the great purge of all their middle management, they had tons of managers at the time and it's just a culture drag. If you have too many managers for the size of your company or the size of your departments then things are going to get toxic and political. Managers try to manage and control, they need to insert themselves into the process, because they're not usually the ones actually doing the work. This isn't to say managers aren't useful, or that they don't do work; but you need to balance the ratio of managers that you have otherwise you're just going to create an environment where nothing gets done.

ID: gzw1wys

Too many chiefs and not enough indians, as the old saying goes. Never a good thing, really gums up the works.

9 : Anonymous2021/05/29 16:15 ID: gzvt7q6

Bulldozer could have been competitive (with the high clocks) against sandy bridge if the final products actually met the design goals

Bulldozer cores were supposed to be wider and not worse than K10, probably due to the crappy 32nm process AMD had

10 : Anonymous2021/05/29 11:43 ID: gzv29yv

I wish Jim Keller was my dad. He feels like a modern day Flynn (from Tron, for the uninitiated).


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