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Should I buy ECC memory? (2015)

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Re: Should I buy ECC memory? (2015)

#141
post #124

Earlier quoted context omitted.

It's significantly more expensive, usually around 30-100% more, depending on capacity. IMO not worth it on a desktop, possibly worth it on a home server or a serious workstation. Plus your CPU and motherboard has to support it, which is a pain with Intel's consumer lineup.

Good thing ryzen supports ECC OBO. Just waiting on motherboard support for it.

If you're not worried about certain chip features and power draw, last gen server equipment is very cheap.

Re: Should I buy ECC memory? (2015)

#142
post #55

While I was at Google, someone asked one of the very early Googlers (I think it was Craig Silverstein, but it may've been Jeff Dean) what was the biggest mistake in their Google career, and they said "Not using ECC memory on early servers." If you look through the source code & postmortems from that era of Google, there are all sorts of nasty hacks and system design constraints that arose from the fact that you could…

Google had done extensive studies[1]. There is roughly 3% chance of error in RAM per DIMM per year. That doesn't justify buying ECC if you have just one personal computer to worry about. However if you are in data center with 100K machines each with 8 DIMM, you are looking at about 6K machines experiencing RAM errors each day . Now if data is being replicated then these errors can propogate corrupted data in unpredic…

That data set covers 2006-2009 and the ram consisted of 1-4GB DDR2 running at 400-800 MB/S. Back when 4GB was considered a beefy desktop, consumers could get away with a few bit-flips during the lifetime of the machine. Now my phone has that much RAM and a beefy desktop consists of 16-32 GB of RAM running at 3GB/s.

It's time we start trading off the generous speed and capacity gains for a some error correction.

Re: Should I buy ECC memory? (2015)

#143
post #13

Earlier quoted context omitted.

There is a hidden cost of ECC with regards to the chipset. None of the cheap chipsets support it, so on any home build, it's going to be expensive.

Fortunately the new AMD Ryzen processors support ECC in the memory controller, unfortunately none of the boards seem to be testing/certifying it yet and the UEFI on a lot of the boards is a mess right now. Hopefully more consumer boards support/certify it since it is already there on the memory controller.

The Asrock 370 boards officially support ECC, though I've read that various BIOS/UEFI versions don't: https://www.reddit.com/r/Amd/comments/655e7v/all_asrock_am4_... People are reporting that the Asrock 350 boards do too. Gigabyte lists some ECC modules on the compatibility list but some report that it isn't working right.

Re: Should I buy ECC memory? (2015)

#144
post #124

Earlier quoted context omitted.

It's significantly more expensive, usually around 30-100% more, depending on capacity. IMO not worth it on a desktop, possibly worth it on a home server or a serious workstation. Plus your CPU and motherboard has to support it, which is a pain with Intel's consumer lineup.

Good thing ryzen supports ECC OBO. Just waiting on motherboard support for it.

Lots of Ryzen motherboards support ECC.

http://www.asrock.com/mb/AMD/X370%20Killer%20SLIac/#Specific...

Re: Should I buy ECC memory? (2015)

#145
post #20

A better question is why /shouldn't/ you use ECC memory? Generally the answer to this is any context where you legitimately do NOT care about your data at all, but you still care about costs. This predominately devolves in to consumption only gaming systems. In all other cases everyone would be better served (in the long run) by buying ECC RAM.

My main issue is that it isn't just a choice between ECC memory and not, but I'd also need a different motherboard and processor, right?

Re: Should I buy ECC memory? (2015)

#146

An old article from DJB worth perusal: http://cr.yp.to/hardware/ecc.html It's also worth noting that not all ECC (SECDED) is created equal: ChipKill™ and similar might not survive physical damage because of likely shorts of the data bus but a single malfunctioning chip producing/experiencing higher hard error rate is possible from which to recover. Also, it'd be really cool if some shop a-la BackBlaze blogged about l…

PS: Random-crazy thought.. it's curious with reduction of costs via Moore's law improvements that there aren't yet formally-verified, zero-knowlege systems which can end-to-end prove they performed computation/real-world side-effects and/or continue to safely store data. Why blindly trust anyone or any company with data that can be seized, lost or misused when distributed computation, communication and storage can be…

Storage, [yes](https://storj.io/). Computation ... sure if you don't mind the server viewing the contents of your computation and can verify the results. Sadly, fully homomorphic systems incur waaaay too much overhead so you are constrained in what you can do (i.e. specialized DBs, zkSNARKs, etc).

Then, of course, there is the problem of network latency and bandwidth costs vs just keeping it all on one datacenter.

Re: Should I buy ECC memory? (2015)

#148
post #98

I reproduced this by bit-squatting cloudfront.net after reading about it. So many memory errors! http://dinaburg.org/bitsquatting.html Loved the variety as well. Sometimes though requests came to me the Host header was correct!

Fascinating article. Did you ever find a reason for the different ios results?

Based on source IPs I would say that cheaper RAM = more error prone RAM.

Re: Should I buy ECC memory? (2015)

#149

I reproduced this by bit-squatting cloudfront.net after reading about it. So many memory errors! http://dinaburg.org/bitsquatting.html Loved the variety as well. Sometimes though requests came to me the Host header was correct!

This Defcon 21 presentation from Robert Stucke did something similar with google's domains, plus other stuff. A great watch if you've got a spare 40 minutes!

https://www.youtube.com/watch?v=yQqWzHKDnTI

Re: Should I buy ECC memory? (2015)

#150

Earlier quoted context omitted.

How much more expensive is ECC ram? I don't have it and I've never experienced obvious issues, if it's a lot more expensive it's not really worth it for the once or twice the desktop will likely experience an actual issue

Should be about 1/8th more since it's just a 72-bit bus for carrying 64-bits data and 8-bits check. Or rather, your dimm will have 9 chips instead of 8. How they get you is Intel will sell you a xeon which is the exact same die as an i5 in a different package for more money.

Depends what you need - you can pick up older gen Xeon chips for cheap and the performance often isn't that much worse than modern consumer grade stuff. If you're looking to build a consumer-level NAS or home server, Avoton is pretty cheap and takes ECC RAM.
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