3 ms·

It's really not cool how RAM these days is advertised and sold by it's potentially possible XMP overclock speed instead of the Jedec speed it's actually rated f

It's really not cool how RAM these days is advertised and sold by it's potentially possible XMP overclock speed instead of the Jedec speed it's actually rated for.

_a_a_a_ 4y ago
Maybe for home use but I really doubt it's sold that way for servers.
toast0 4y ago
Selling based on JEDEC ratings only would be unhelpful. Not sure about ddr5, but ddr4 JEDEC ratings only go to 3200; there's good reasons to want to run Ryzen chips at 3600 or higher. I'd rather buy something where the packaging tells me it should work at the speed I want to run it, than have to figure out which skus people say tends to work, when all the boxes just say 3200. Yeah, if you start getting higher speeds, it becomes more a question of if the memory controller on the cpu, the wiring on the motherboard, and the ram itself will work together at that speed, which you can't guess from just the number on the ram packaging. It would be nice if JEDEC offered more ratings, but given that they don't, I'll take the XMP numbers.
- Dalewyn 4y ago
  I'm not sure why it has to be either-or. Give us both the rated JEDEC clocks and timings and the manufacturer overclock clocks and timings. To use the DDR4-3200 example, it is far more difficult than it should be to figure out whether that's JEDEC 3200MHz or actually JEDEC 2166MHz with 3200MHz XMP overclocking.
Night_Thastus 4y ago
XMP is not like an old-school overclock. Assuming the motherboard isn't faulty, you're pretty much guaranteed to get the clock speeds advertised with no instability. It's plug and play.
- superkuh 4y ago
  It is supposed to be plug and play but a good fraction of the time it is not. I've been assembling computers from parts since the mid-90s and I never had any trouble with RAM till my latest builds with DDR4 trying to use default XMP settings. In fact I've never gotten a DDR4 computer to run at the advertised XMP speed and timings even when the mobo fully supports it. I always have to back off a few hundreds of MHz and loosen the timings to prevent memtest86+ errors. I've observed others on IRC computer hardware channels reporting the same problems (selection bias, of course, only people with problems ask questions). You've been lucky (or you're using latest and greatest mobos).
  - toast0 4y ago
    I've had good luck with DDR4 and reasonable speeds working with XMP, but sometimes the XMP data has a voltage lower than what the packaging indicates, and setting the voltage according to the packaging works a lot better. But I'm just getting DDR4-3600, not DDR4-5000 or something; and I think all my DDR4 setups are 1 dimm per channel, which helps. I didn't ever get DDR3 XMP to be happy though.

It's really not cool how RAM these days is advertised and sold by it's potentially possible XMP overclock speed instead of the Jedec speed it's actually rated for.

_a_a_a_ 4y ago

Maybe for home use but I really doubt it's sold that way for servers.

toast0 4y ago

Selling based on JEDEC ratings only would be unhelpful. Not sure about ddr5, but ddr4 JEDEC ratings only go to 3200; there's good reasons to want to run Ryzen chips at 3600 or higher. I'd rather buy something where the packaging tells me it should work at the speed I want to run it, than have to figure out which skus people say tends to work, when all the boxes just say 3200. Yeah, if you start getting higher speeds, it becomes more a question of if the memory controller on the cpu, the wiring on the motherboard, and the ram itself will work together at that speed, which you can't guess from just the number on the ram packaging. It would be nice if JEDEC offered more ratings, but given that they don't, I'll take the XMP numbers.

Dalewyn 4y ago
I'm not sure why it has to be either-or. Give us both the rated JEDEC clocks and timings and the manufacturer overclock clocks and timings. To use the DDR4-3200 example, it is far more difficult than it should be to figure out whether that's JEDEC 3200MHz or actually JEDEC 2166MHz with 3200MHz XMP overclocking.

Night_Thastus 4y ago

XMP is not like an old-school overclock. Assuming the motherboard isn't faulty, you're pretty much guaranteed to get the clock speeds advertised with no instability. It's plug and play.

superkuh 4y ago
It is supposed to be plug and play but a good fraction of the time it is not. I've been assembling computers from parts since the mid-90s and I never had any trouble with RAM till my latest builds with DDR4 trying to use default XMP settings. In fact I've never gotten a DDR4 computer to run at the advertised XMP speed and timings even when the mobo fully supports it. I always have to back off a few hundreds of MHz and loosen the timings to prevent memtest86+ errors. I've observed others on IRC computer hardware channels reporting the same problems (selection bias, of course, only people with problems ask questions). You've been lucky (or you're using latest and greatest mobos).
- toast0 4y ago
  I've had good luck with DDR4 and reasonable speeds working with XMP, but sometimes the XMP data has a voltage lower than what the packaging indicates, and setting the voltage according to the packaging works a lot better. But I'm just getting DDR4-3600, not DDR4-5000 or something; and I think all my DDR4 setups are 1 dimm per channel, which helps. I didn't ever get DDR3 XMP to be happy though.