Ryzen CPU HyperThreads break if 100% busy and interrupted to top of Memory

it happens when SMT is disabled

>Epyc is on a new stepping of the silicon, it's possible this is already fixed on it. (Threadripper is not, however)

that's assuming they caught this bug, which i doubt is the case because it's only discovered now rather than being documented in the errata.

https://www.reddit.com/r/Amd/comments/6rmq6q/epyc_7551_minin...

I'm not really all that big a fan of APUs, their niche is decent integrated graphics cheap, but for low-end serveresque or office-box usage I'd go with the Pentium G4560. It has ECC too if that's your thing. Rumors are that 4C8T i3s may be coming with Coffee Lake too - obviously no efficiency step up but it'll be price competitive with Ryzen (right now the i3s and locked i5s usually aren't good value).

You can sometimes still find X99 stuff on clearance too - the 5820K and 6800K are essentially power- and performance-competitive with Ryzen 5 in all respects, plus you also get quad-channel RAM and more lanes, the caveat being they're usually more expensive than Ryzen 5. But, they're also mature at this point, and v3 Xeons should even be starting to come out from server farms within a year or two.

The bigger Coffee Lake parts will be tinkerer's specials. You'll need to delid for sure, I totally bet Intel isn't going to do shit about the TIM problem on SKL-X. It's probably going to be nearly as big a die as X99 was anyway, if they could possibly manage to solder it they really need to do it. Either way it's going to eat a lot of power, but they should be fast. Kaby with more cores is a pretty potent formula.

Of course there's no guarantees, SKL-X turned out to be shit for gaming.

Normally Ryzen 5 and 7 dominate the value charts here of course. Intel's products are really only compelling for people who game at the moment. X99 is good, the 7700K is good, the 7600K is good (really guys, hyperthread only gets you roughly ~10% average speedup in games). The 7350K can be OK for ricer low-end builds - if your game of choice is single-threaded (virtually any Source game) it really cooks, and Microcenter has it for $130 (minus a $30 bundle discount if you want a mobo). The G4560 (2C4T) was a value changer for Intel in the low-end market, it's a good office box and it has ECC support for light server usage too. There are rumors Intel is choking down on production because it's eating up i3 sales, which is hilarious, because a price cut is exactly what 2C4T needs.

But really, if you count out Ryzen and Threadripper that leaves Bulldozer, Fusion processors, and Intel products. Bulldozer is mature but slow and hot and really only works well on things like video encoding. Fusion is a laptop processor, and the Pentium beats it. Intel has nothing worthwhile in the "boring office box" category between the G4560 and the X99 range, their consumer stack is almost only relevant in gaming otherwise.

Yeah, I was super bummed when I heard Threadripper was going to be on the older stepping. Otherwise I'd be really interested in it (especially with official ECC support). That would be a sick little server box. I'm thinking about doing a NAS build on X99 instead - I can build something basically the size of a DS1817+ but with 2x16 lane single slots free for NVMe sleds/infiniband.

https://pcpartpicker.com/list/dBPWqk <-- this but with a used processor

The other thing is I'd love to see more done with Kabini. There definitely is a place for very cheap shitbox computers - you used to be able to get a AM1 mobo + Athlon 5350 CPU for $40 together, you could do a full low-end build for $200. I was really disappointed to see it go. The CPU supports ECC but none of the motherboards do, give me an ECC mITX server board with an onboard SAS controller! It would be very competitive with the Avoton C2550/C2750 line (which are randomly shitting themselves nowadays unfortunately...) and could be used for NAS appliances. DDR3 is dead now... but Kabini can support DDR3L.

Normally there is an incoming backlog, i.e. the kernel accepts (SYN/ACKs) incoming connections before accept(2) happens; accept(2) just pops a connection off the backlog.

Unfortunately, I have an nVidia GPU, and I use the nouveau driver, because apparently using nVidia's proprietary driver on Tumbleweed is a huge PITA. Maybe I will have to bite that bullet eventually, though.

If it is marginal timing in some part of the chip, that combined with statistical process and environment variations, and the increasingly tiny geometries (which serve to amplify the variation) mean the problem could really occur quite randomly. Modern CPUs are pushing the limits in more ways than one, and IMHO this is what happens when they go too far.

Such uncertainty is bad. segfault is not the only issue, the risk of having some interally corrupted data is the biggest risk.

I've stopped using the Ryzen junk I bought on its release day.

If IRETQ is failing to RET under load then this is a huge issue. How do you even fix that? Load balance interrupt processing across cores? Throttle any process in a tight loop? It's all ugly hacks. AMD needs to fix this.

There is also a POC for invoking this on Windows on GitHub I'm really wondering what this issue will lead too.

it mentions something that I really worried about - Intel knowingly requested its own validation efforts to be reduced so they can place half baked products onto the market faster. pretty sad that both Intel/AMD are seem to be cutting corners to just be a little bit faster in the competition.