6 ms·
ECC RAM by design is more expensive. Usually every 8 bits need a 9th parity bits, so you need 9/8ths more RAM to support ECC. Plus you need to make the parity c
by kop316 8y ago
ECC RAM by design is more expensive. Usually every 8 bits need a 9th parity bits, so you need 9/8ths more RAM to support ECC. Plus you need to make the parity calculation for everytime you go to RAM.
Whether it's needed or not...that's use case dependent.
- pedrocr 8y agoI know ECC is more complex, my hypothesis was that in volume the difference would be small enough to not care and that we're only stuck with non-ECC RAM because of path dependence. >Whether it's needed or not...that's use case dependent. Even for gaming, having your game crash/misbehave because of bit flips is at the very least annoying. But maybe this is uncommon enough that it doesn't make enough difference?
- blattimwind 8y agoGaming systems are often overclocked and aren't really stable often enough in the first place.
- kllrnohj 8y ago> Even for gaming, having your game crash/misbehave because of bit flips is at the very least annoying. But maybe this is uncommon enough that it doesn't make enough difference? My gaming system with non-ecc memory will run memtest all day long never spotting a single error. I know these errors can & do happen, but I'm fairly certain the number of crashes I've experienced that would have been prevented using ECC memory is single digits at most. But ECC being in general slower than non-ECC? Well that's very noticeable.
- agapon 8y agoECC is useless until it is not. Just like insurance, backups, etc.
- kllrnohj 8y agoThe failure risk of ECC is significantly lower than a lack of insurance of backups, though. Drive fails and no backups? Potentially terabytes of data vanishes. House burns down and no insurance? Hundreds of thousands of dollars to repair. No ECC and a bit flips? Nothing happens, program crashes, or maybe a single file gets corrupted in an unrecoverable way.
- agapon 8y agoAnd maybe that file happens to be an important encryption key. Or maybe a whole filesystem gets corrupted if some important metadata is. Or maybe your system develops a hardware problem over time, like an oxidized CPU pin or a contact in a memory slot and then you are getting flaky bits on a regular basis. ECC is useless until you experience a problem of those kinds. And many people will never do. But some will. I have.
- zozbot123 8y agoIt's not just 9/8 more RAM, but 9/8 more memory bandwidth on the bus. So, yes, a pretty nasty performance hog for typical use.
- p1necone 8y agoI wonder how feasible it would be to build ECC ram where you could toggle the ECC part and just use the extra capacity if you so wished.
- WrtCdEvrydy 8y agoECC is a hardware level implementation usually.
- shawnz 8y agoBut why does it have to be implemented in the DIMMs? Why not in the memory controller, such that any RAM could be used with or without parity?
- WrtCdEvrydy 8y agoIf you do that, you're moving the cost on to the motherboards and increasing the cost for something most consumers won't get any advantage out of.
- agapon 8y agoECC logic is implemented in the memory controller (in the CPU these days). The ECC DIMM just provides extra chips to store ECC bits. And the motherboard, if it supports ECC, provides just extra data lanes that connect the extra DIMM chips to the appropriate pins on the CPU.
- vbezhenar 8y agoIs your typical performance limited by memory bandwidth? Or rather by latency?
- wongarsu 8y agoIn other words, a 32GB ECC memory stick has to include an extra 4GB for parity. That's actually a price I would be willing to pay.
- vbezhenar 8y agoSo you will need to pay 360$ instead of 320$. Many people would choose cheaper memory. I guess, almost everyone except some PC enthusiasts (last time I discussed it, the majority of PC enthusiasts thought that ECC on desktop is not needed, so they wouldn't want to pay for it). I agree that ECC is nice to have, but price is real.
- wongarsu 8y agoRAM prices already vary by more than 12%, and it seems like there is no shortage of people paying premium for brand recognition, different board colors (green is "out"), useless heat sinks etc. I think there would be plenty of people willing to pay extra for ECC (some for peace of mind, some because they need it, some just to feel superior)
- JohnBooty 8y agoThe market segment of "people who are willing to pay a premium for computing devices" is pretty vast, isn't it? Most people would be fine with a $200 Chromebook, $500 bare-bones Windows notebook, or a garden-variety PC from 2007 but millions of us choose to pay more because we value the additional things that newer, more powerful computing devices give us. Lots of professionals and enthusiasts gladly pay large premiums for higher-spec gear, even when the improvements are quite small, because those small improvements are enjoyed over many thousands of hours of lifetime use. Perhaps more to the point, you already see gamers paying premiums for higher-specced memory to enable their overclocking and tweaking endeavors. So I definitely think there's a market of people who'd pay more for ECC...
- vbezhenar 8y agoI guess they will pay for higher frequency, but for ECC? Not so much. It won't help to achieve higher geek rating after all. I might be totally wrong about it, of course.