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DDR4 vs. DDR5 Memory Performance For Intel Core i5-12600K Alder Lake On Linux

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  • bug77
    replied
    Originally posted by kylew77 View Post
    Correct me if I'm wrong, I may not have understood what I was reading but doesn't all DDR 5 come with ECC built in? Or some form of ECC? Really a fan of the technology especially as we put more and more RAM into systems like laptops. Almost all my RAM at work is ECC DDR 4 and DDR 3.
    ECC for DDR5 is a misnomer. It's form of error correction which is actually mandated for DDR5 to function. But it's not the same as server memory ECC and it's not a replacement either.
    There are good articles out there, you should check them out. In a nutshell, DDR5 offers nowhere near the safety of ECC memory, but it is a little safer in operation that DDR4 is.

    It's really nothing to worry about, last I checked some stats, as a home user you're only encountering 1 (one!) bit flip per year on average.
    Last edited by bug77; 23 November 2021, 05:41 PM.

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  • xnor
    replied
    Originally posted by uid313 View Post
    The DDR5 used in this benchmark was the slow 4400. There is also DDR5-4800 and DDR5-6400 which are faster. Hopefully later even faster DDR5 variants will be announced.
    And you will get free extra latency with that!! The throughput tests are nice for some applications, but they don't show the regressions in DDR5's increased latency for applications that have a large working set and do more random accesses, especially if the amount of data for each access is small.

    DDR4 4400 CL19 = 8.6ns
    DDR5 4400 CL36 = 16.4ns (+90%)

    This can only be partially mitigated with larger CPU caches.

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  • chuckula
    replied
    Originally posted by torsionbar28 View Post
    Has some form of ECC baked in, but it's all behind the scenes, you have no visibility into it. Kind of like the internal error correction baked into an SSD. Servers will still use real ECC that utilizes additional memory chips, and where the OS has visibility into errors and corrections.

    The baked-in ECC is to protect against errors that actually occur within an individual chip and really point to the fact that individual memory cells are becoming less reliable with smaller lithography & faster clocks to the point that adding complexity to each DRAM die became necessary.

    Traditional ECC with the extra chip and ECC in the memory controller is still necessary to handle errors that occur during transfer of data back & forth from the CPU, which can't be addressed by the in-chip ECC.

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  • chuckula
    replied
    I will say that while DDR5 is still expensive and hard to find [just like DDR4 was when it was new... and DDR3 when it was new... etc. etc.] the fact that DDR5 at equal clocks is actually outperforming DDR4 is a good sign for the technology. Of course DDR5 will eventually scale to near or maybe above 10,000 speeds over time, but usually when the lowest-tier of a new DDR standard is compared to the highest-tier of its predecessor the results actually favor the older standard, while you are showing the opposite results here.

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  • torsionbar28
    replied
    Originally posted by kylew77 View Post
    Correct me if I'm wrong, I may not have understood what I was reading but doesn't all DDR 5 come with ECC built in? Or some form of ECC? Really a fan of the technology especially as we put more and more RAM into systems like laptops. Almost all my RAM at work is ECC DDR 4 and DDR 3.
    Has some form of ECC baked in, but it's all behind the scenes, you have no visibility into it. Kind of like the internal error correction baked into an SSD. Servers will still use real ECC that utilizes additional memory chips, and where the OS has visibility into errors and corrections.

    Leave a comment:


  • torsionbar28
    replied
    Originally posted by uid313 View Post
    The DDR5 used in this benchmark was the slow 4400. There is also DDR5-4800 and DDR5-6400 which are faster. Hopefully later even faster DDR5 variants will be announced.
    It will be. New memory always starts at around the same MT's as the previous gen, and climbs from there. These are the officially supported JEDEC speeds over each generation. Of course the aftermarket will push the limits a bit more as well:

    DDR2 introduced at 400, eventually climbing to 1066.
    DDR3 introduced at 1066, eventually climbing to 2166.
    DDR4 introduced at 1600, eventually climbing to 3200.
    DDR5 introduced at 4400, eventually climbing to ????.

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  • kylew77
    replied
    Correct me if I'm wrong, I may not have understood what I was reading but doesn't all DDR 5 come with ECC built in? Or some form of ECC? Really a fan of the technology especially as we put more and more RAM into systems like laptops. Almost all my RAM at work is ECC DDR 4 and DDR 3.

    Leave a comment:


  • TemplarGR
    replied
    It is really funny when people don't really read the same graphs i am reading. The performance difference is significant, even at 4400mhz which is a lot slower than the officially supported 4800mhz. It is almost the equivalent of a new architecture IPC gains (and i am pretty sure as the schedulers improve we are going to see much higher gains from DDR5). Hardly something to scoff at. Someone who is buying a brand new cpu which its cheapest model currently costs higher than 300 euros and also needs to use an expensive new motherboard, really has no reason to cheap out on DDR5, if it is in stock. It is not like overclocked DDR4 is cheap. Try getting DDR4 at higher than 3600mhz and see how much you need to pay. If you are into getting an Alder Lake NOW, you are among the people who want the best performance and don't care about pricing very much, that means you should get DDR5.

    Otherwise, if you care about price vs performance, Rocket Lake is simply put the best desktop processor line currently. AMD cpus at the moment are priced way higher than they should be. Rocket Lake pricing especially for the i5s is great and you can get affordable motherboards and DDR4 for a cheap system that is not that far behind in performance from the latest and greatest.

    So, as i correctly said in another thread, right NOW, if you are going Alder Lake, get DDR5, if you want DDR4, get Rocket Lake. Things will change in the coming months with cheaper mobos for Alder Lake, cheaper CPU models, and more affordable DDR5.

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  • uid313
    replied
    The DDR5 used in this benchmark was the slow 4400. There is also DDR5-4800 and DDR5-6400 which are faster. Hopefully later even faster DDR5 variants will be announced.

    Leave a comment:


  • Tuxee
    replied
    2% between DDR5-4400 and readily available DDR4-3600... Not exactly rousing.

    Leave a comment:

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