Hello all,
I am building a WRX80 workstation and realized Threadripper Pro support registered ECC. I know all fundamental and theoretical differences, but 16Gb modules are available both Registered and Unbuffered, so the question is - is there any practical advantage in reliability or performance in using Registered ECC memory over Unbuffered?
More capacity dimms.
There are 256GB modules out there.
For me, bufferd ddr4 is often way cheaper used on ebay then anything else.
Especially here in germany, udimm ecc is atrociously expensive and pretty hard to get.
I understand that Registered memory comes with larger capacities - but I am comparing specifically 16Gb modules. Also Unbuffered memory is at least x1.5 times cheaper then Registered with similar capacity - and this is the reason I am asking the question - don’t want to waste money.
I am as well buying it in Germany (to Ireland) - and it’s available in stock in assortment.
you have to distinguish between between buying and comparing prices of new product vs used.
And i’m not entirely sure what you mean with unbuffered:
Do you mean Buffered ECC vs Unbuffered ECC?
Or Buffered ECC vs Unbuffered non ECC?
In case that the last one is what you mean, the Buffered ones are probably much more expensive compared new to new.
If you are looking at the first one, in my opinion unbuffered is actually at least as expensive and harder to get.
looking at Geizhals.de, one of the best comparison pages there is, Samsung RDimm 16GB 2133 is the cheapest module available at 59€ and the next one i can see that isn’t clearly RDimm is 65€.
If you start searching for Udimm ECC; Oh boy, 90€ a 16GB Stick.
Ebay prices usually shoot to 50€ and obve for udimm ecc 16gb sticks.
I looked closer, prices have skyrocketed, what the frick.
iirc, buffered is a way for memory to achieve higher capacities with lower load on the memory controller. Load reduced takes this even further.
If you want high capacity dimms, you need to get registered or load reduced dimms, as the memory controller on your CPU can only handle directly talking to so many memory ICs per channel.
I would think unregistered would actually produce better latency, if anything. Registered low-capacity dimms are probably older, or for systems that only take registered ECC.
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For the benefit of those that aren’t aware: “registered” == “buffered”.
Registered/buffered ECC memory has only one technical advantage outside of hyper-specialised fields: Support for Larger Capacities.
Registered/buffered ECC memory has only one technical disadvantage outside of hyper-specialised fields: Higher Latency (typically one clock cycle).
If you don’t need larger capacities, and don’t want higher latency, then don’t get registered/buffered ECC.
It is the presence (or lack) of ECC support that impacts reliability. Registered/buffered (versus unregistered/unbuffered) has no impact on reliability outside of hyper-specialised fields.
If you are sure that 128GB is going to be enough for you, then you can go with (up to) 8x16GB Unregistered/Unbuffered ECC modules, perhaps save some money in the process, and enjoy a single-digit percentage point advantage in latency.
It is (apparently) possibly to put non-ECC memory into a WRX80. But if you are building a “workstation” for professional use, you’d have to be certifiably insane to install that junk. Non-ECC memory should only be installed on systems that deal with data of limited or no value (e.g. gaming rigs).
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Thnx. That explains everything.
It’s just I saw your video on Asus WRX80 where it was said that “it should ideally be used with registered ECC”, so I thought there may be something else other than capacity.
128 (8x16) is enough for my needs so I will go with unbuffered.
unbuffered NON ECC or unbuffered ECC?
Again, Geithals.de clearly shows that unbuffered ECC is substantially more expensive then Buffered ECC.
If you are going unbuffered Non ECC, i agree with level1, you have to be insane to not go ECC for a “Workstation” where you actually do work.
makes your bones rage doesnt it? 
the reason i am on this forum , quality info summarized so nicely
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