DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix • Hacker News Board

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#121

Post by LeifCarrotson » Tue, Oct 06, 2020, 5:36 PM UTC

verall wrote: post #101

klodolph wrote: post #85

Earlier quoted context omitted.

Because the manufacturing techniques have improved? You can see the effects of better manufacturing techniques in other parts.

DRAM is not transistors. Transistors have gotten much smaller much faster than DRAM.

The thing that's gotten smaller is the minimum feature size on a silicon wafer. The same types of etching and doping processes can be used to create many integrated circuits.

DRAM chips are integrated circuts that consist of individual transistors and capacitors for each bit, plus the wiring and logic to read, refresh, and write to those bits. They're substantially transistors.

It's true that logic, power, analog, flash, DRAM, SRAM, and mixed signal ICs do have some significant differences, and some manufacturers optimize for a subset of those capabilities, but they're similar enough that if one industry advances leaps and bounds (like Flash storage and low-power processing have).

So why does DRAM lag behind the others?

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#122

Post by lostlogin » Tue, Oct 06, 2020, 5:37 PM UTC

Taek wrote: post #114

verall wrote: post #99

Earlier quoted context omitted.

This is a bad comparison. DRAM margins are razor thin and unlike transistors, DRAM has not gotten much smaller, which is the main cost savings gained from process improvements. Instead, server and accelerator vendors want ever faster and higher performance DRAM, and so these performance gains trickle down to consumers, but nothing is driving price down. People on here literally think Moore's is a natural law and if c…

Hasn't the DRAM industry gotten in trouble with regulators multiple times for fixing prices?

They have. Giving the industry the benefit of the doubt after decades of price fixing is generous at best.

“To date, five manufacturers have pleaded guilty to their involvement in an international price-fixing conspiracy including Hynix, Infineon, Micron Technology, Samsung, and Elpida.”

It’s claimed to be a very high margin industry and supply is artificially constrained to maintain that margin.

https://en.m.wikipedia.org/wiki/DRAM_price_fixing

https://www.extremetech.com/computing/283081-dram-manufactur...

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#123

Post by throw0101a » Tue, Oct 06, 2020, 5:40 PM UTC

DCKing wrote: post #118

wmf wrote: post #110

Earlier quoted context omitted.

I expect Intel to still cripple some aspect of DDR5 ECC on consumer chips; maybe it will correct errors but the memory controller won't report them. Or maybe it's possible to disable ECC even though it's already implemented. I also expect servers to use two levels of ECC to provide chipkill and also to keep server RAM more expensive than consumer.

Ryan Smith in the link above seems to suggest error correction will be done transparently anyway, so it seems like it won't reported to the OS. So it doesn't look like Intel could cripple it even if they wanted to.

> Ryan Smith in the link above seems to suggest error correction will be done transparently anyway, and it won't reported to the OS.

I once heard a rant from someone on how not reporting this to the OS is really bad for diagnosing issues, even soft errors that are auto-healed. (It could have been from Bryan Cantrill, but couldn't say for sure.)

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#124

Post by Klinky » Tue, Oct 06, 2020, 5:41 PM UTC

varispeed wrote: post #84

toast0 wrote: post #64

Earlier quoted context omitted.

I think this makes sense for IBM, but probably not for AMD and Intel. AMD and Intel are putting out new chips every year (even if they're just Skylake refreshes), so it's not too big of a deal to change the memory interface, and they are capable of putting in two flavors of DDR support when some flexibility is needed. For IBM, I don't think they release incremental chip designs each year, so it makes more sense for t…

It is pretty much the current greed driven technology. Company doesn't want to invest in proper FPGA technology that will allow reconfiguration of chipsets on the fly, but instead they want people to buy new chipsets every year or so and preferably make the old ones obsolete (not resellable)

AMD and Intel have released multiple DDR4 chipsets over there last 4~ years. The chipsets releases have hardly been related to RAM type support. Typically it's power or PCIe related, with Intel being the worst offender.

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#125

Post by kasabali » Tue, Oct 06, 2020, 5:47 PM UTC

bagpuss wrote: post #97

kasabali wrote: post #92

Earlier quoted context omitted.

They aren't price fixing anymore. Now it's called CapEx and water start.

water start?

> Wafer start means the release of one wafer to the fabrication process for processing.

> https://www.lawinsider.com/dictionary/wafer-start

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#126

Post by BeefySwain » Tue, Oct 06, 2020, 5:48 PM UTC

Sebb767 wrote: post #80

brixon wrote: post #11

Earlier quoted context omitted.

"For bandwidth, other memory manufacturers have quoted that for the theoretical 38.4 GB/s that each module of DDR5-4800 can bring, they are already seeing effective numbers in the 32 GB/s range. This is above the effective 20-25 GB/s per channel that we are seeing on DDR4-3200 today." That looks like a 20%+ improvement IF you are bottle-necking on DDR4.

So, it's worth upgrading if you're running Redis or Dwarf Fortress :)

My understanding is that Dwarf Fortress is memory LATENCY limited, not bandwidth. Definitely could be wrong though.

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#127

Post by kasabali » Tue, Oct 06, 2020, 5:50 PM UTC

mc32 wrote: post #89

kasabali wrote: post #88

Earlier quoted context omitted.

What I read around is that's not the enterprise ECC, it's more akin to ECC bits used in flash memory. It'll allow manufacturers to play fast and loose with memory.

So in other words, error prone memory modules don’t have to be tossed and can be sold because they will be self correcting...?

That's what I understand. Frequencies will be higher and manufacturing process denser later in DDR5 lifecycle so they must be expecting more errors.

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#128

Post by DCKing » Tue, Oct 06, 2020, 5:53 PM UTC

throw0101a wrote: post #123

DCKing wrote: post #118

Earlier quoted context omitted.

Ryan Smith in the link above seems to suggest error correction will be done transparently anyway, so it seems like it won't reported to the OS. So it doesn't look like Intel could cripple it even if they wanted to.

> Ryan Smith in the link above seems to suggest error correction will be done transparently anyway, and it won't reported to the OS. I once heard a rant from someone on how not reporting this to the OS is really bad for diagnosing issues, even soft errors that are auto-healed. (It could have been from Bryan Cantrill, but couldn't say for sure.)

I do think that there will still be some people interested in ECC detection and reporting, but that's not really why I'm interested in ECC memory. The dividing line "enterprise = error correction with monitoring / non-enterprise = silent error correction" is much more sensible than "non-enterprise = no error correction at all, good luck" IMO.

Isn't the primary reason why people are looking into diagnostics is because it's very hard to determine whether ECC is working in the first place? Because it depends on the particular hardware setup? If the spec states that all DDR5 is supposed to have internal error correction anyway, then I'm happy to take for granted error correction is working until I read about the scandals of non-spec cheap DDR5 :)

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#129

Post by TedShiller » Tue, Oct 06, 2020, 5:57 PM UTC

It's great to hear that new versions of Dance Dance Revolution are still being developed. I love that game, gives you a great physical workout.

Re: DDR5 Is Coming: First 64GB DDR5-4800 Modules from SK Hynix

#130

Post by chungus_khan » Tue, Oct 06, 2020, 6:00 PM UTC

louhike wrote: post #40

Zenst wrote: post #34

Earlier quoted context omitted.

Depends upon what you pay - certainly the second market will see a surge and drop in prices. If you can tech on top end 5 years later, it's not that bad and sure wallet friendly. Also factor in that it usually takes a few years until the full potential of a platform it tapped, so the PS4 in it's prime days for games.

I do not understand your argument as the parent post is saying the PS5 can play PS4 games. So the PS5 will also benefit from the great games coming on PS4. The prices of the games would be the same, you would benefit from the same experience of the devs developing on the PS4. The only disadvantage is that the PS5 will be pricer. And it will also be less ecological-friendly if you intend to buy an used PS4. But that's…

I've seen a few people who ride one generation back and buy used. It means you can get the console incredibly cheap (and can choose the best/most reliable variant), have a huge catalogue of games to explore (which are also incredibly cheap), and already know which games are standout and which are misses. Doesn't work if you're into the latest multiplayer games though.