4 ms·

> One of the things that drove mass SSD adoption was the experience was plainly better. Even the most illiterate user could see how fucking fast an SSD machine

by paulmd 4y ago

> One of the things that drove mass SSD adoption was the experience was plainly better. Even the most illiterate user could see how fucking fast an SSD machine booted and how much more responsive they were. > SSD to Optane? There's no practical difference. No, that's false. That's true of NVMe in general but Optane specifically is really good at the low-queue-depth random-4k workloads that characterize consumer use-cases. Optane actually is extremely fast at things like OS patches that normally take a few minutes even on NVMe flash let alone sata. They boot faster, applications launch faster, etc. Normally those things don't have lots of parallel threads running so queue depth is low and flash doesn't perform very well (as in, SATA and NVMe are nearly indistinguishable), but Optane really helps. Is that worth paying 10x as much for? No, probably not, but that's the real problem, not the general lack of performance. Optane is actually noticeable specifically for being the first thing that actually provides a noticeable improvement above and beyond SATA SSDs for consumer use-cases. It's just also too expensive to be justifiable.

PaulHoule 4y ago
Although "client computing" is still the largest source of Intel revenue, and its scale was what made the x86 architecture able to crush legacy server architectures, I think Intel takes it for granted relative to the data center. It would have been very interesting to see an "all Optane" tablet device but it would have been hard to make work: a modest amount of storage would be affordable but it would take a clean sheet OS to maximize performance and economics. I was skeptical about Optane DIMMs. Optane SSDs were the fastest SSD you'd ever seen, but the DIMMS were the slowest you'd seen in a while. Although they were faster than Optane SSDs, they were slower than RAM if you replaced RAM 1-1. Optane was denser and cheaper than ordinary RAM so you could pack your machine with a huge quantity of slow RAM. If access patterns and cache behavior permit, you could build systems of a certain problem size that perform well with Optane. Advanced programming techniques can help. For every big problem there are many little problems (don't need Optane) and some problems are too big for Optane. Many problems in the size range for Optane can be implemented to conserve RAM and have access patterns that stream well to mass storage. Thus Optane faced fierce competition.
- monocasa 4y ago
  > and its scale was what made the x86 architecture able to crush legacy server architectures, I think Intel takes it for granted relative to the data center This is true; the reason is that the margins on the data center chips are what keeps the lights on.
- paulmd 4y ago
  In practical terms the only real use for Optane DIMMs was very high capacity RAM systems. Optane let you get 512GB in a stick when LRDIMM was 128GB. And of course you can still go multisocket etc too. So you run the same software, but in large-VRAM scenarios that couldn't be handled optimally by LRDIMMs without paging. Things like SAP HANA and so on. But a system that only makes sense in super high end configurations is setting an uphill battle for itself. You can't even put together a demo machine without using one of a handful of processors at the top of Intel's stack, how do you even demo that to your boss as a concept? And in the end the commodity solutions just ended up outpacing it at lower cost, flash still sucks at random but it's generally fine and people don't want to pay the extra $500 for optane on their 1tb drive. Software getting entirely rewritten for NVRAM is a pipe dream lol. Maybe you could have defined a "high range" ala HIMEM that is persistent across boots and will never be allocated, just used it as a block device so your SAP database would never unload, but, yeah, there are non-trivial problems.
deleted 4y ago
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by paulmd 4y ago

PaulHoule 4y ago

Although "client computing" is still the largest source of Intel revenue, and its scale was what made the x86 architecture able to crush legacy server architectures, I think Intel takes it for granted relative to the data center. It would have been very interesting to see an "all Optane" tablet device but it would have been hard to make work: a modest amount of storage would be affordable but it would take a clean sheet OS to maximize performance and economics. I was skeptical about Optane DIMMs. Optane SSDs were the fastest SSD you'd ever seen, but the DIMMS were the slowest you'd seen in a while. Although they were faster than Optane SSDs, they were slower than RAM if you replaced RAM 1-1. Optane was denser and cheaper than ordinary RAM so you could pack your machine with a huge quantity of slow RAM. If access patterns and cache behavior permit, you could build systems of a certain problem size that perform well with Optane. Advanced programming techniques can help. For every big problem there are many little problems (don't need Optane) and some problems are too big for Optane. Many problems in the size range for Optane can be implemented to conserve RAM and have access patterns that stream well to mass storage. Thus Optane faced fierce competition.

monocasa 4y ago
> and its scale was what made the x86 architecture able to crush legacy server architectures, I think Intel takes it for granted relative to the data center This is true; the reason is that the margins on the data center chips are what keeps the lights on.
paulmd 4y ago
In practical terms the only real use for Optane DIMMs was very high capacity RAM systems. Optane let you get 512GB in a stick when LRDIMM was 128GB. And of course you can still go multisocket etc too. So you run the same software, but in large-VRAM scenarios that couldn't be handled optimally by LRDIMMs without paging. Things like SAP HANA and so on. But a system that only makes sense in super high end configurations is setting an uphill battle for itself. You can't even put together a demo machine without using one of a handful of processors at the top of Intel's stack, how do you even demo that to your boss as a concept? And in the end the commodity solutions just ended up outpacing it at lower cost, flash still sucks at random but it's generally fine and people don't want to pay the extra $500 for optane on their 1tb drive. Software getting entirely rewritten for NVRAM is a pipe dream lol. Maybe you could have defined a "high range" ala HIMEM that is persistent across boots and will never be allocated, just used it as a block device so your SAP database would never unload, but, yeah, there are non-trivial problems.

deleted 4y ago

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