[HN Gopher] How many AMD RX 7900 XTX's are defective?
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How many AMD RX 7900 XTX's are defective?
Author : ingve
Score : 41 points
Date : 2023-01-11 21:50 UTC (1 hours ago)
(HTM) web link (www.jeffgeerling.com)
(TXT) w3m dump (www.jeffgeerling.com)
| wzy wrote:
| Does this problem extend to the 7900 XT?
| snarfy wrote:
| Apparently not. "... The reference model for
| the step-down Radeon RX 7900 XT appear to be fine as well." [1]
|
| [1] - https://www.pcworld.com/article/1446335/amd-confirms-
| radeon-...
| pifm_guy wrote:
| Heat pipes - the large copper tubes between hot chips and
| heatsinks - are actually hollow and usually filled with some
| liquid/gas mixture. That's often butane or something with a
| lowish boiling temperature at lowish pressures.
|
| They work by having the liquid boil at the hot end, the gas flow
| along the pipe, condense back to a liquid at the cold end, and
| then the liquid flow back.
|
| That last step, the liquid flowing back, is the critical one.
| With gravity, the liquid can gush back really fast, and loads of
| heat can be transferred.
|
| But if the card is the wrong way up, then it relies on the liquid
| wicking back along some clothlike material coating the inside of
| the pipe. That's a far slower process. Therefore the heat that
| can be dissipated this way is much lower.
|
| That's why heat pipe performance is dramatically affected by
| orientation.
|
| The designers of this card will have been aware of that, but
| likely decided a small performance hit for sustained workloads
| was probably worth it.
| onli wrote:
| It's not a small performance hit. The card is throttling a lot
| and ramping up the fans up to 1000RPM more than usual because
| cooling fails completely. There were report about cards failing
| while testing this (e.g. in the der8auer video), but ofc it's
| not possible to be sure that the card broke because of this.
| It's possible though.
|
| This is not an expected failure mode the engineers would have
| been okay with even if it did not kill cards. No one would be
| okay with the heatpipe drying up like this.
| formerly_proven wrote:
| The card der8auer had which failed was very clearly a VRM
| failure.
| onli wrote:
| * * *
| wmf wrote:
| The thing is that the vapor chamber is working perfectly fine
| upside down in most of these cards. It sounds like a
| manufacturing problem not a design flaw.
| formerly_proven wrote:
| As per der8auer and GamersNexus, AMD claims to know which batches
| of cards have underfilled vapor chambers yet at the same time
| refuses to recall them and wants customers to RMA instead.
| causality0 wrote:
| _AMD originally stated that 110degC junction temps were normal,
| but seemed to back off that statement as more evidence_
|
| Letting the marketing assholes control how you respond to a
| crisis is a great way to destroy your credibility forever.
| [deleted]
| crote wrote:
| I think part of the issue is that silicon is _intentionally_
| being run increasingly hotter over the last few years.
|
| The temperature sensors have gotten good enough that the
| hardware can auto-boost right up to the physical limits. The
| card will essentially "overclock" itself until it either 1)
| hits a temperature limit, or 2) hits a power draw limit.
|
| A high temperature _is indeed_ normal, and customer support /
| marketing is aware of this. You have to look at the power drawn
| to reach that temperature to determine if there is a cooling
| issue, but such technical details are probably lost on most
| low-level CS folks.
| [deleted]
| dhruvdh wrote:
| 110-degree junction temperatures are indeed nothing to worry
| about, it's just the card shouldn't be throttling and reach
| these temperatures at these frequencies and power draw.
|
| When a new product is released, it is common for there to be a
| learning curve for support in terms of what is normal and what
| is not. They are not engineers.
|
| This is just an unfortunate coincidence - batches were tested
| in vertical orientation, which is normal for test benches, but
| most users use the card in horizontal orientation.
|
| Orientation affecting temperatures is unexpected and
| unintuitive, so this was missed. Cause is rumoured to be
| insufficient coolant in vapor chamber for affected batches.
|
| Please don't read too much into this low-effort rant. I don't
| blame the author, it's okay to be frustrated when a big
| purchase doesn't go their way, but if you have a large
| following you should be more mindful of your words.
| Sweepi wrote:
| The cause is no longer a Rumor, there has been an official
| statement by AMD:
|
| "It all comes down to a small batch of our vapor chamber
| acually have an issue - not enough water."
| jjulius wrote:
| >This is just an unfortunate coincidence - batches were
| tested in vertical orientation, which is normal for test
| benches, but most users use the card in horizontal
| orientation.
|
| Why would you choose to test your product in a manner that is
| completely opposite from how most people would use it?
| Granted, I'm asking from a place of ignorance, but that just
| seems... dumb. I'd be curious to learn why my perspective
| might be wrong.
| pifm_guy wrote:
| If you really need that last few percent of performance, just get
| a 90 degree pcie adapter so you can run the card at its most
| efficient angle ...
|
| Hardly seems something to complain about - I mean it does work in
| all orientations.
|
| Will you next complain that cigarette lighters burn your fingers
| if you use them upside down?
| omegote wrote:
| The standard position for graphics card has been horizontal,
| for many, many years. I don't think the standard position for a
| cigarrete lighter is upside down, to begin with.
|
| Next, for your "solution" to work you need a special case that
| allows for the card to be installed vertically, which is not
| common.
| sbierwagen wrote:
| >just get a 90 degree pcie adapter
|
| And also buy a second PC case that actually has the slots for a
| 90 degree mount? Otherwise you'll need to take a hacksaw to the
| back of your computer.
| shmerl wrote:
| Better to use custom models anyway.
| morjom wrote:
| a decently known PC hardware overclocking channel, der8auer, did
| a few hands on investigative videos on these kind of cards that I
| found interesting. maybe you will too. they do content in both
| english and german.
|
| https://youtube.com/@der8auer-en
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(page generated 2023-01-11 23:00 UTC)