Corsair Dominator Platinum RGB DDR5 leak, Alongside Details of Kingston's DDR5 Modules

[metalslaw]

I doubt that will happen.
JEDEC timings for DDR4 3200 is 22-22-22 and as far as I know, there are no DDR 3200 modules will 11-11-11 timings. The closets seems to be 14-14-14.
As such, I wouldn't expect DDR5 4000 with JEDEC timings of 40-40-40 to be able to drop to 20-20-20, but we might see 32-32-32 at some point in the future.

Attached is an old graphic, but it shows that as ram speed goes up, to have the same actual latency, you basically just run higher timings, to get the same actual latency.

So for say ddr2 1600 ram, with 8:8:8 timings, you end up with an actual latency of 10ns. This is the same 10ns latency as say ddr3 2400 ram with 12:12:12 timings. And again with ddr4 3200 ram with 16:16:16 timings, which is also 10ns.

Generally, each ddr gen has jumped 800mhz, and to keep the same latency, the (main) timings jump by 4.

Thus, I'd expect the sweetspot for ddr5 to be around cl20 4000mhz, with 20:20:20:xx timings, within around 6-8 months time (as crappy timing ram always come initially on any new ddr gen).

 

[TheLostSwede]

Attached is an old graphic, but it shows that as ram speed goes up, to have the same actual latency, you basically just run higher timings, to get the same actual latency.

So for say ddr2 1600 ram, with 8:8:8 timings, you end up with an actual latency of 10ns. This is the same 10ns latency as say ddr3 2400 ram with 12:12:12 timings. And again with ddr4 3200 ram with 16:16:16 timings, which is also 10ns.

Generally, each ddr gen has jumped 800mhz, and to keep the same latency, the (main) timings jump by 4.

Thus, I'd expect the sweetspot for ddr5 to be around cl20 4000mhz, with 20:20:20:xx timings, within around 6-8 months time (as crappy timing ram always come initially on any new ddr gen).

Sorry, but I can tell you for certain, that it won't happen. Sub 30 timings isn't likely for the first generation of DDR5 and 20 won't happen at 4000MHz, maybe 3600.

 

[AusWolf]

Attached is an old graphic, but it shows that as ram speed goes up, to have the same actual latency, you basically just run higher timings, to get the same actual latency.

So for say ddr2 1600 ram, with 8:8:8 timings, you end up with an actual latency of 10ns. This is the same 10ns latency as say ddr3 2400 ram with 12:12:12 timings. And again with ddr4 3200 ram with 16:16:16 timings, which is also 10ns.

Generally, each ddr gen has jumped 800mhz, and to keep the same latency, the (main) timings jump by 4.

Thus, I'd expect the sweetspot for ddr5 to be around cl20 4000mhz, with 20:20:20:xx timings, within around 6-8 months time (as crappy timing ram always come initially on any new ddr gen).

That's a good point.

As always, I'll join the game a few generations later when technology has matured, standard speeds and latencies have been set, and prices have fallen to acceptable levels - just like I did with DDR, DDR2, 3 and 4.

Sorry, but I can tell you for certain, that it won't happen. Sub 30 timings isn't likely for the first generation of DDR5 and 20 won't happen at 4000MHz, maybe 3600.

Maybe you're right, we'll see.

To everyone: Let's not forget about DDR5's other improvements, like the 2x32 bit bus per channel (instead of 1x64), or the on-module voltage controller. I think these are all things that will need a lot of benchmarking, tweaking and supplemental technology (software) to be built to really shine, which definitely won't happen in the early generations.

 

[TheLostSwede]

Maybe you're right, we'll see.

To everyone: Let's not forget about DDR5's other improvements, like the 2x32 bit bus per channel (instead of 1x64), or the on-module voltage controller. I think these are all things that will need a lot of benchmarking, tweaking and supplemental technology (software) to be built to really shine, which definitely won't happen in the early generations.

DDR5 does at least for now, have a lot of peculiar limitations.

Anandtech go a list of officially supported speeds from Intel, but please read their comments that goes with the image.

Intel 12th Gen Core Alder Lake for Desktops: Top SKUs Only, Coming November 4th

www.anandtech.com

So if you want to go high clock, you need a board with only two DIMM slots, such as the Gigabyte Z690 Aorus Tachyon.
The reason I bring up that board specifically, is because Gigabyte has handily provided a list of what they've tested and at what clocks speeds for that board.

Z690 AORUS TACHYON (rev. 1.0) Support | Motherboard - GIGABYTE Global

Lasting Quality from GIGABYTE.GIGABYTE Ultra Durable™ motherboards bring together a unique blend of features and technologies that offer users the absolute ...

www.gigabyte.com

Considering the default DDR5 Voltage is 1.2V and they're pusing 1.5-1.55V to reach certain clocks and timings, it's not likely we're going to see anything close to what people are hoping for at stock Voltage or even slightly increased Voltage any time soon. The best 4800MHz modules have CAS latency of 36, with a 4000MHz Corsair kit hitting a CAS latency of 32, although oddly enough at 1.1V. On the other hand, 6600MHz at CAS 36 requires the aforementioned 1.55V and 7000MHz at CAS 40 is at 1.5V.
Anyhow, you can peruse the list at your own leisure and maybe you'll reach a different conclusion than me, but I don't believe we'll ever see CAS 20 at 4000MHz.

Then there's this. Lots more bandwidth, but then again, that's no surprise, but even at 6000MHz which should be CAS 40, DDR4 4800MHz has much better latency.

https://twitter.com/i/web/status/1453259686116007941

 

[oxrufiioxo]

I think it still seems much more impressive starting point than what we got with DDR4.

 

[TheLostSwede]

I think it still seems much more impressive starting point than what we got with DDR4.

I guess it comes down to what you can afford to buy. Judging by Gigabyte's list for the Tachyon board, it seems like we can expect higher clocks sooner rather than later, whereas timings aren't likely to improve much for now.

 

[InVasMani]

It looks like DDR5 CAS latency will be roughly double or more the CAS latency of DDR4 at the same frequency and usually a fair amount more at least for now though I think it'll change in time to be close. They doubled bank groups so that's possibly the reason for it to retain stability, but the performance uplift should be worth the trade off.

 

[RandallFlagg]

So if you want to go high clock, you need a board with only two DIMM slots, such as the Gigabyte Z690 Aorus Tachyon.
The reason I bring up that board specifically, is because Gigabyte has handily provided a list of what they've tested and at what clocks speeds for that board.

Z690 AORUS TACHYON (rev. 1.0) Support | Motherboard - GIGABYTE Global

Lasting Quality from GIGABYTE.GIGABYTE Ultra Durable™ motherboards bring together a unique blend of features and technologies that offer users the absolute ...

www.gigabyte.com

Holy crap, DDR5-7000 is in their tested list, using a Gigabyte Aorus brand DDR5-5200 kit :

This is the kit they used :

AORUS Memory DDR5 32GB (2x16GB) 5200MT/s Besonderheiten | Memory - GIGABYTE Austria

GIGABYTE, Chassis, Thermal Solution, Power Supply, Optical Device, TV Tuner Card, gamer, PSU

www.gigabyte.com

Also those looking at RAM may find this comparison of DDR4 and DDR3 at the Skylake launch of interest:

The Intel 6th Gen Skylake Review: Core i7-6700K and i5-6600K Tested

www.anandtech.com

I think it still seems much more impressive starting point than what we got with DDR4.

From what I gathered on the old DDR4/DDR3 review, it is, if we are talking about below DDR4-4000 kits. The increase in speed seems to be much higher. I seriously doubt someone running say DDR4-4266 C18 is going to be impressed though. Us peons with DDR4-3200 C16 will probably be quite happy.

 

[AusWolf]

DDR5 does at least for now, have a lot of peculiar limitations.

Anandtech go a list of officially supported speeds from Intel, but please read their comments that goes with the image.

Intel 12th Gen Core Alder Lake for Desktops: Top SKUs Only, Coming November 4th

www.anandtech.com

So if you want to go high clock, you need a board with only two DIMM slots, such as the Gigabyte Z690 Aorus Tachyon.
The reason I bring up that board specifically, is because Gigabyte has handily provided a list of what they've tested and at what clocks speeds for that board.

Z690 AORUS TACHYON (rev. 1.0) Support | Motherboard - GIGABYTE Global

Lasting Quality from GIGABYTE.GIGABYTE Ultra Durable™ motherboards bring together a unique blend of features and technologies that offer users the absolute ...

www.gigabyte.com

Considering the default DDR5 Voltage is 1.2V and they're pusing 1.5-1.55V to reach certain clocks and timings, it's not likely we're going to see anything close to what people are hoping for at stock Voltage or even slightly increased Voltage any time soon. The best 4800MHz modules have CAS latency of 36, with a 4000MHz Corsair kit hitting a CAS latency of 32, although oddly enough at 1.1V. On the other hand, 6600MHz at CAS 36 requires the aforementioned 1.55V and 7000MHz at CAS 40 is at 1.5V.
Anyhow, you can peruse the list at your own leisure and maybe you'll reach a different conclusion than me, but I don't believe we'll ever see CAS 20 at 4000MHz.

Then there's this. Lots more bandwidth, but then again, that's no surprise, but even at 6000MHz which should be CAS 40, DDR4 4800MHz has much better latency.

View attachment 222740
View attachment 222741

https://twitter.com/i/web/status/1453259686116007941

Aaah, so the official support for 4800 MHz has got a bunch of ifs at the end. While being limited to one DIMM per channel is not a big problem, it makes one suspect some stability issues. One more reason for me to skip this generation.

 

[TheLostSwede]

Aaah, so the official support for 4800 MHz has got a bunch of ifs at the end. While being limited to one DIMM per channel is not a big problem, it makes one suspect some stability issues. One more reason for me to skip this generation.

It's not even just one DIMM per channel, but also only one slot per channel, in theory.
It doesn't actually seem to be a real world issue though, but it does seem like speeds top out at around 6000-6200MHz even on higher-end boards that have more than two physical slots.
It also seems like either XMP has to be used, or you have to manually try and tweak things, as the system will automagically drop the speed if you use certain configurations of RAM.

* Speed dropping policy according to Intel processor specification (XMP disabled):
DDR5 4800 MHz speed drops down to 4400 MHz when 2 DIMMs of the same channel are populated e.g., DDR5_A1/ _A2. Please adjust your setup according to the recommendation above.
DDR5 4800 MHz speed drops down to 4000 MHz when 4 DIMMs are populated (1Rx8/ x16 modules).
DDR5 4800 MHz speed drops down to 3600 MHz when 4 DIMMs are populated (2Rx8/ x16 modules).

MSI seems to have different limitations compared to Gigabyte and this is their two DIMM board. Not QVL as yet.

• Max. overclocking frequency:
  • 1DPC 1R Max speed up to 6800+ MHz
  • 1DPC 2R Max speed up to 5600+ MHz

ASRock has next to zero modules in their QVL and haven't tested anything over 4800MHz in it.

Supports DDR5 non-ECC, un-buffered memory up to 6400+(OC)*

Asus has equally limited information at the moment, but the ROG Maximus Z690 Apex, which is also a two DIMM board claims similar speeds. Not memory QVL for any boards as yet.

2 x DIMM, Max. 64GB, DDR5 6600(OC)/6400(OC)/ 6200(OC)/ 6000(OC)/ 5800(OC)/ 5600(OC)/ 5400(OC)/ 5200(OC)/ 5000(OC) / 4800 Non-ECC, Un-buffered Memory*

So far, it seems like Gigabyte has the lead, as they've tested the Z690 Aorus Tachyon up to 7000MHz.

1. Support for DDR5 7000(O.C.) / 6600(O.C.) / 6400(O.C.) / 6200(O.C.) / 6000(O.C.) / 5800(O.C.) / 5600(O.C.) / 5400(O.C.) / 5200(O.C.) / 4800 / 4000 MHz memory modules

 

[AusWolf]

It's not even just one DIMM per channel, but also only one slot per channel, in theory.
It doesn't actually seem to be a real world issue though, but it does seem like speeds top out at around 6000-6200MHz even on higher-end boards that have more than two physical slots.
It also seems like either XMP has to be used, or you have to manually try and tweak things, as the system will automagically drop the speed if you use certain configurations of RAM.

That's too much headache for me. No bueno. No worries, though, I think I'm alright with Rocket Lake for a couple more years.

 

[InVasMani]

Gigabyte put DP 1.2 on their boards sadly. The Mini-ITX seems to have DP 1.4 however, but I don't want mini-ITX plus it costs more as well.

 

[Ahhzz]

Guys, getting off topic here. Wander back that way, please. thanks!

 

[tabascosauz]

View attachment 222740
View attachment 222741

https://twitter.com/i/web/status/1453259686116007941

Wait wait......what is the DDR4 running on in that picture? All those numbers are beyond abysmal. Write is 3200CL16-level, Read is 4400CL16-level, and copy is 3733CL16-level, and 64.6ns?????

Cezanne APUs scale to 4800 without breaking 1:1 IF if you use a dGPU, and they already start breaking the 50ns mark at only like 4133CL16. I'm already at 48ns @ 4333CL16 with 67GB/s R/W......

And then there's 4800 on Comet Lake which is in the 35ns range if not lower, with good bandwidth

I mean, yes the bandwidth for DDR5 looks to be in the right place, and latency looks decent (considering everything is just going to be desynced IMC like RKL going forward). That Copy number looks nice and consistent, real bandwidth should be good. But lordy this isn't how you do a comparison, with laughably unstable hardware.......

 

[TheLostSwede]

Wait wait......what is the DDR4 running on in that picture? All those numbers are beyond abysmal. Write is 3200CL16-level, Read is 4400CL16-level, and copy is 3733CL16-level, and 64.6ns?????

Cezanne APUs scale to 4800 without breaking 1:1 IF if you use a dGPU, and they already start breaking the 50ns mark at only like 4133CL16. I'm already at 48ns @ 4333CL16 with 67GB/s R/W......

And then there's 4800 on Comet Lake which is in the 35ns range if not lower, with good bandwidth

I mean, yes the bandwidth for DDR5 looks to be in the right place, and latency looks decent (considering everything is just going to be desynced IMC like RKL going forward). That Copy number looks nice and consistent, real bandwidth should be good. But lordy this isn't how you do a comparison, with laughably unstable hardware.......

No idea, the person who posted that didn't respond to the people asking.
Bandwidth good, latency, not so much.