Comment by morelikeborelax | Hacker News Reader

Comment by morelikeborelax | Hacker News Reader

morelikeborelax

I've had ECC on my workstations since 2006 when Intel forced it on DP systems due to FB-DIMMs. Being that I have had a good number of correctable memory errors over the past decade I don't feel I can go back to not having it, wouldn't make any sense when the cost is so low. It was also a case that I couldn't get non-ECC 8GB and 16GB DIMMs when I built some of my systems, so it just was a matter of fact that I had to use it.

Do people need it? Nah probably now for systems that can handle crashing, but you'd be nuts to not use it in servers or systems running long jobs - it's just a single insurance payment on your system that gives a remote chance of protection.

Sadly there are very few studies in to it that show how modern DIMMs still get errors that are correctable. Manufacturing processes are much better, but they haven't eliminated the need for it.

I do enjoy the "why would I need it, I've never had memory errors" attitude though when people likely have no idea why their application or OS crashed. And the accounts of people who eventually diagnose memory errors after weeks of random crashes which would have been reported immediately if they had ECC.

This is a big dilemma I have. I'm trying to build a workstation similar to Nvidia's reference design for deep learning:

https://developer.nvidia.com/devbox

I will be doing deep learning and other ML GPU-powered tasks. Plus some long running high-memory I/O intensive tasks.

Note that Nvidia's build does not employ ECC RAM. And it's a quite expensive machine. Mine will be only a fraction of the cost ($4.5k), with just one Titan X. It's possible to afford a Xeon, but this comes at the compromise of buying slower hardware. What shall I do?

Intel's segmentation of the market, limiting the amount of RAM you can use in regular CPUs and removing support for ECC sucks.

They likely don't use ECC ram because it's a Dev box targeted at development and testing... ie. it's not going to need to be up and running for a large stretch of time and/or data corruption is acceptable.

Otherwise, their reference system is no different from a "high end" gaming rig (ie. not a "server").

But some deep learning tasks can easily take 4 or 5 days in a humble setup with a GPU or 2. Therefore it might be advisable to run ECC?

Yes, you are correct. I would use ECC in that situation if it were my system.

The point I was making about the reference Nvidia setup was that it's targeted at development, which means starting and stopping the system often, etc. So ECC wouldn't be of much use in that sense, and it would only serve to make Nvidia's reference system more expensive. I don't think it's a sign they don't believe it should be used.

Your GPU doesn't have ECC so the point is moot

Yes, there is a risk, but maybe not enough to jeopardize the test.

NNs are adaptive so they should be able to tolerate the odd flip in the weight matrices during training.

I'm seeing the E5-1650v3 at around the same price as the i7-5930K and the Supermicro X10SRA significantly cheaper than the Asus X99-E WS but it's not SLI certified.

But with slight overclocking the i7 will offer significantly better performance at the same price point. (edited)

Also try moving to newer processes / more cores. The price gap becomes big.

Currently actually only Skylake Xeons support AVX-512, the shiniest and newest incarnation of SIMD. No desktop i3, i5 or i7 does that.

No one is using MMX anymore, but even it is supported by all the Xeons made in last 15 years. Xeons have had SSE just as long as other Intel CPUs.

So what you said is not true at all.

True, I stand corrected. Thanks.

AMD has much cheaper points of entry to ECC.

yeah I was noticing this, AMD is much more ECC friendly whereas Intel segments their markets hard by arbitrarily disallowing ECC platform use on common consumer (read: not-Xeon) CPUs. Unfortunately AMD is still quite a bit slower than Intel these days, but if you are doing work that is GPU rather than CPU intensive it might not matter.

> disallowing ECC platform use on common consumer (read: not-Xeon) CPUs

this hasn't really been true since Haswell. Now even low-end Celerons and Pentiums support it.

One may suspect that some Celeron/Pentium/i3 SKUs support ECC just so that Intel doesn't have to manage low-volume very-low-end E3 SKUs. And then you run into the fact that the cheapest server motherboard is double the price of a cheap desktop one.

From what I can tell, some Celeron/Pentium/i3 SKUs support it because AMD was killing Intel in certain NAS applications thanks to the fact that their low-end chips had ECC.

Even then, not all MBs support it... Most of the higher end Asus boards do, with AMD CPUs. The difference in power usage is pretty significant... Going from an FX-8350 to an i7-4790K was a significant power/heat improvement, for a faster CPU. The i3-5010U in my htpc is pretty awesome for what it does as well.

It really depends on the tasks if you NEED it... I wouldn't to a byo nas ever again... I would suggest that a lot of workloads don't need it.

That said, the additional cost should be nominal at this point, and I don't quite get why it isn't standard. It's like the coprocessors in the early 90's eventually became a critical integrated piece.

Core i3's have ECC support.

Yes, but many of the consumer grade motherboards do not. (you have to step up to a xeon in most cases)

Low end server/workstation motherboards are quite cheap and plentiful nowadays. Even some of the low-end Pentiums have ECC support so there is little reason not to.

Any examples of a cheap Intel motherboard that supports ECC?

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DE...

There seems to be plenty of options in the sub-$200 range.

I don't believe the Core i3's have ECC support. See [1]. My understanding is that the i3's (and i5's and i7's) differ from Xeons in that the do not have ECC support.

[1] https://communities.intel.com/message/282073

There are a lot of i3's with ECC support, even some Pentiums, Celerons and Atoms have ECC support. I see them used often in cheap NAS builds, seems just that specific one in your link didn't have it, not i3's in general.

http://ark.intel.com/search/advanced?s=t&ECCMemory=true

According to the link which Orf pasted below: https://aws.amazon.com/ec2/faqs/

Amazon use ECC in all server instances including their GPU compute machines. If you're part of a company or university ask Intel for a Xeon sample. They sometimes hand them out for free.

Do Titans have ECC? If the bulk of the calculation will be done on the GPU, adding ECC to the main board may not matter.

That's a good point. AFAIK they don't. But Teslas and Quadros do.

Why would Nvidia stick four graphics cards in a system when each card uses 16 lanes of pcie and the processor maxes out at 40 lanes?

It depends on algorithm/implementation but some do not require much communication with CPU once you put data on GPU.

I just switched out a tired old Dell Precision T5400 (~7 years old, ran 24hrs a day but began randomly crashing) which has ECC memory for a new box built out of bits and no ECC memory. It'll be interesting to see what difference this makes regarding error rates and hardware failures.

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