Abandoned - Very frustrating RAM problem - Page 1
Forum section: electronics / general

author: hap2001
author_rank: Regular Contributor
timestamp: September 19, 2024, 01:57:06 pm
content: Edit: The laptops in question were sent back, thank you all who tried to help me.Hi friends, I'm having a RAM related problem that I cannot diagnose by myself.So I have 2 laptops (A,B) of same model, and 2 sets of RAMs (X,Y) of different model. (Yes 2 sets and 4 sticks total, but to keep the problem not too messy, I always test them within the same set.)Originally it's A+X and B+Y. Both exhibit random unstable behaviors (A+X more severe), such as crash and lock up, which I later guessed it's RAM related.I use Memtest86+ to check: A+X errors a lot, B+Y I forgot...I exchanged them: both A+Y and B+X have no errors.I exchanged them back: A+X errors less than first time, B+Y no error.I cleaned both DIMM and socket with ethanol, not fixed.Since the randomness, I suspect heat related, but then I tested A+Y with vent blocked, so it's hotter than first test, still no error.One strange thing is, the errors are all across the address range (unlikely to be real bad/weak cells), but stay constant at the same bit within same test, and shift a little across different test/reboot.Also I don't understand how it can differ with 2 laptops of exact same model and config.I'm really lost here, can anyone help me?

author: Bryn
author_rank: Regular Contributor
timestamp: September 19, 2024, 02:46:55 pm
content: I've had problems with RAM sticks before (although that was over 15 years ago) so, as complicated as your issue is (especially when the different RAM sticks had behaved for every test you did with them between the two laptops), I can assume that there might be physical damage in either of them or both or if they're in absolute perfect condition, considering lowering their voltage settings in compliance to both the laptops' BIOS. Also, updating the BIOS in them both would be beneficial if you haven't done so already.

author: hap2001
author_rank: Regular Contributor
timestamp: September 19, 2024, 03:37:02 pm
content: Thank you!All 4 sticks are in good physical condition, at least I cannot see any damage with naked eyes.The laptops cannot set voltage in BIOS.Both laptop have latest BIOS version.More info:Laptops are HP Probook 455 G4 with AMD A9-9410.They have only single channel IMC.

author: nctnico
author_rank: Super Contributor
timestamp: September 19, 2024, 04:02:57 pm
content: Probably the wrong type of memory or cheap garbage. I'd suggest to get quality memory from an A-brand like Kingston. Kingston has a tool on their website to find the right (compatible) memory for your laptops.

author: wraper
author_rank: Unknown
timestamp: September 19, 2024, 04:09:45 pm
content: If RAM is marginally stable, slight difference in RAM supply voltage or another CPU specimen can make the difference between system being stable or unstable. It probably can be fixed by increasing timings (in bios if it allows it or by modifying SPD).

author: eutectique
author_rank: Frequent Contributor
timestamp: September 19, 2024, 04:19:49 pm
content: Quote from: hap2001 on September 19, 2024, 01:57:06 pmDo you always insert one set the same way? I mean, x1 -> slot 1, x2 -> slot 2. Or did you not care?When did the problems start? Are these refurbished laptops? 455-G4 was released in 2016. What were they doing in the past 8 years? Compiling Linux kernel 24/7 or being an office browser from 9 to 5? Are you sure the problem is memory and not CPU?2 slots (supposedly) and 4 sticks give 8 permutations. Try them all, record the result. Repeat for the second laptop.Or buy yourself new memory of a reputable brand from a reputable seller. Or a new CPU.

author: Someone
author_rank: Super Contributor
timestamp: September 19, 2024, 10:47:06 pm
content: Quote from: wraper on September 19, 2024, 04:09:45 pmEven expensive "high end" (S)DRAM could have been sold with narrow electrical margins from new, its a bit of a lottery as to how long ram will last even ECC workstation/server parts.

author: Psi
author_rank: Super Contributor
timestamp: September 19, 2024, 10:55:57 pm
content: Probably a timing issue, being a laptop you usually cannot change all the timing and latency settings. So there probably isn't a way to fix it.The ram likely just isn't compatible with that laptop with the ram timing settings it uses.Maybe if you pair one stick with another stick that is of a slower speed it may force both to use different timing and then work fine, but meh, probably not worth paying around with.

author: thm_w
author_rank: Super Contributor
timestamp: September 19, 2024, 10:59:01 pm
content: Just to check:- What RAM testing software is being used and how long is it running?Some RAM errors can take many hours to show up.

author: Bryn
author_rank: Regular Contributor
timestamp: September 20, 2024, 06:18:47 am
content: Quote from: nctnico on September 19, 2024, 04:02:57 pmYou know, I was going to say theexactsame thing, but I wasn't sure if that was really the case for him.Quote from: thm_w on September 19, 2024, 10:59:01 pmHe said he used Memtest86+ to test them in his OP.

author: hap2001
author_rank: Regular Contributor
timestamp: September 20, 2024, 10:02:34 am
content: Quote from: nctnico on September 19, 2024, 04:02:57 pmI never use garbage brand parts.Quote from: wraper on September 19, 2024, 04:09:45 pmSadly as a typical laptop BIOS, there's no way to change those settings.Quote from: eutectique on September 19, 2024, 04:19:49 pmYes I do always insert them the same way.They are used laptops from ebay, I have the RAM sticks before the laptops and they were working well in Dell machines, I do suspect the laptops instead of the RAM.However it's strange to have 2 laptops fail the same way.Quote from: thm_w on September 19, 2024, 10:59:01 pmMemtest86+ v7, 1 pass.

author: nctnico
author_rank: Super Contributor
timestamp: September 20, 2024, 10:06:54 am
content: Quote from: hap2001 on September 20, 2024, 10:02:34 amWell, there is your problem: the memory simply isn't compatible with your laptops! Case closed.If you are lucky, the manufacturer of the memory has a compatibility list.

author: eutectique
author_rank: Frequent Contributor
timestamp: September 20, 2024, 10:17:22 am
content: Quote from: nctnico on September 20, 2024, 10:06:54 amOr laptops surfaced on ebay because they start to hang up.

author: nctnico
author_rank: Super Contributor
timestamp: September 20, 2024, 10:25:57 am
content: Quote from: eutectique on September 20, 2024, 10:17:22 amThen it would be a common problem which is easy to discover by using Google to find out if memory problems are common problems for the particular laptop model. Having two laptops with the exact same problem is rare.

author: radiolistener
author_rank: Super Contributor
timestamp: September 20, 2024, 11:39:19 am
content: I had a similar issue with a motherboard based on an Intel chipset and processor. I tried a bunch of different memory sticks from various brands and stores, and all of them failed. The worst failures occurred with different types of Kingston sticks - memtest would show errors almost immediately. Samsung was more stable, but after running memtest for 5-10 hours, it would still show an error. Then I tried overclocking memory from Corsair with passive cooling, and surprisingly, it didn't fail - it successfully passed the tests in memtest for 7 days.I think the issue might be some kind of incompatibility issue between certain types of memory and the memory controller.

author: Bryn
author_rank: Regular Contributor
timestamp: September 20, 2024, 12:07:17 pm
content: See... everyone's saying it now. Incompatible memory.But why were they included in these laptops in the first place, I'll never know... and the one responsible for it should get a slap on the wrist for that.

author: wraper
author_rank: Unknown
timestamp: September 20, 2024, 01:07:33 pm
content: ^Unless RAM is actually faulty, "incompatible" in this case means that laptop does not like this memory. Not that it's incompatible by spec. I once had 2 brand new RAM sticks which simply did not work properly in particular PC. RAM tests were fine but it would BSOD at least once in 1-2 weeks. Even underclocking or leaving just a single stick did not fix the issue. Swapped those with similar sticks in my work PC, and issue got fixed. Work PC had no issue with those either, so I just left it at that.QuoteBecause it worked fine at first glance.Also most of consumer branded RAM is actually factory overclocked to faster clock, tighter timings than RAM chips are rated for. "Good brands" like Kingston don't hesitate doing it either. It's not just XMP, standard SPD is usually overclocked as well. While this usually works fine, it for sure does not help for compatibility with different hardware.

author: Bryn
author_rank: Regular Contributor
timestamp: September 20, 2024, 01:55:42 pm
content: Quote from: wraper on September 20, 2024, 01:07:33 pmSo let me get this straight... laptops or PCs that happen to have incompatible memory, work absolutely fine the first time?Honestly, that's blown my mind a bit but least that's something new I've learnt so thanks for that...

author: wraper
author_rank: Unknown
timestamp: September 20, 2024, 02:14:40 pm
content: Quote from: Bryn on September 20, 2024, 01:55:42 pmIt's supposed to be compatible. However there are so many possible hardware combinations, manufacturers cannot test all possible pieces of hardware from different manufacturers is they work together with no issues. Often compatibility issues get fixed in bios updates if manufacturer was reported of such.

author: eutectique
author_rank: Frequent Contributor
timestamp: September 20, 2024, 02:18:15 pm
content: Quote from: Bryn on September 20, 2024, 12:07:17 pmScroll a bit up to theReply #10. It says literally:They are used laptops from ebay,I have the RAM sticks before the laptopsand they wereworking well in Dell machines

author: Bryn
author_rank: Regular Contributor
timestamp: September 20, 2024, 03:08:15 pm
content: Oh sorry... completely overlooked that. Cheers.

author: thm_w
author_rank: Super Contributor
timestamp: September 20, 2024, 08:55:22 pm
content: Quote from: hap2001 on September 20, 2024, 10:02:34 am1 pass is not enough to show long term reliability.I think the minimum recommended is 3, and the "ideal" is 8 passes.

author: wraper
author_rank: Unknown
timestamp: September 20, 2024, 09:06:11 pm
content: Quote from: thm_w on September 20, 2024, 08:55:22 pmEven if there are no errors after running for 24 hours, it's still not a 100% guarantee that it's actually stable. Just a high chance of it. That's why my main PC has ECC RAM, too much of my nerves wasted on undetectable RAM issues in the past.

author: nctnico
author_rank: Super Contributor
timestamp: September 20, 2024, 10:27:34 pm
content: Quote from: thm_w on September 20, 2024, 08:55:22 pmI'd let it run for 24 hours or 50 passes or so. If that doesn't turn up a problem, the memory is pretty good. Make sure to enable all tests though if they aren't enabled by default. But if you need to use a PC professionally, buy professional hardware from HP or Dell. Not the consumer crap.

author: magic
author_rank: Super Contributor
timestamp: September 21, 2024, 03:55:12 am
content: I have seen bit errors which happened within no more than 30~60 minutes of running one particular software on a machine that perfectly passed as many overnight Memtest86 runs as I wanted. I replaced RAM with another type and it all went away.If it fails Memtest86 it's bad, but Memtest86 doesn't necessarily catch all bad RAM.I'm using ECC since then. Too much nonsense to worry about.And fuck Intel, of course.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 21, 2024, 05:33:25 am
content: Yup. I always run a memtest over the weekend at least. It's not a proof or guarantee of fitness, but if it finds failures, the mem is definitely no good in that configuration.Many motherboards vary in their memory support depending on whether you fill only one pair or both.On full-size desktop motherboards, it is common for the QVL to list fastest timings for only when one pair is used.As an example, on an ASRock X670E Taichi Carrera with an AMD Ryzen 9 7900 (QVL), if you want to use all four sockets, you're limited to 5600 MHz (compared to 7600 MHz you can get when only two are used).Thus, it is not at all strange to me that A+Y and B+X work well, while A+X and B+Y have memory errors, especially with age (tiny SMD chip caps losing capacitance as they age).

author: radiolistener
author_rank: Super Contributor
timestamp: September 24, 2024, 11:25:49 am
content: Quote from: Bryn on September 20, 2024, 01:55:42 pmYes, it depends on the case. In some cases, the memory error will happen every second. In others, it may take at least an hour or two to catch a single error. In the second case, the system may work fine for some time.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2024, 12:21:45 pm
content: Quote from: Nominal Animal on September 21, 2024, 05:33:25 amThis is a different issue. Using DIMM connectors it simply is no longer possible to create a design which supports these high speeds. This is why we'll be seeing more and more Camm memory moduleshttps://en.wikipedia.org/wiki/CAMM_(memory_module). At some point the laws of physics catch up.QuoteDecoupling is primarily through ceramic capacitors and these don't really get bad due to age. Memory is compatible or not. Due to tolerances some combinations will perform better / worse but that means very little in the end.

author: Bryn
author_rank: Regular Contributor
timestamp: September 24, 2024, 01:00:19 pm
content: In case anybody didn't notice the modified thread title, the OP had ultimately decided to send the laptops back (I've seen his first post on this thread just there).Don't know if we should continue discussing his problem in general or have the thread locked, whatever's suitable.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 25, 2024, 07:27:31 am
content: Quote from: nctnico on September 24, 2024, 12:21:45 pmNo. There is a reason why most motherboards support high clock frequencies on one full DIMM channel, but much lower frequencies when both DIMM channels are in use, and it isn't "physics" per se. After all, it is the exact same connectors and physical devices.You can clearly see in the QVL I linked to thatmanyare only qualified to be used to fill one channel (one pair); and very few are qualified to fill both channels (two pairs, four DIMM sticks).(You can argue that of course the base reason comes down to physics, because everything physical comes down to physics, really. Here, the two channels are not independent, but driven by the same memory controller, so the two channels do interact at least electrically. If this is what you call "a different issue", and the physical limitation when using 4 DIMMs instead of just 2, then I'd agree somewhat: to me, it is more like a design limitation in the memory controllers. As the motherboard ages, the memory controller becomes slightly more limited wrt. clock and signal pulse shapes and whatnot that work without errors; MLCC aging is an important part of that.)Quote from: nctnico on September 24, 2024, 12:21:45 pmThey ageenoughto excarberate the differences between individual DIMM sticks. For example, for X5R, it is about 6% after the first 1000 hours of use.Note that I'm specifically referring to the caps on the motherboard, not the ones on the memory sticks. For details on MLCC aging, do check out theWürth Electronic Support Note on MLCC aging, for example. Also note that four years of almost daily use, 8h per day, corresponds to about 10000h of use, so those scales are very relevant here.If this happened with a brand new motherboard and memory, I'd be very suspicious. When it happens with a motherboard that is five to ten years old, Iexpectthis kind of quirks due to aging, and just deal with it; I've built and maintained enough Intel/AMD PCs to have seen this in practice for myself.

author: Someone
author_rank: Super Contributor
timestamp: September 25, 2024, 07:44:28 am
content: Quote from: Nominal Animal on September 25, 2024, 07:27:31 amThe next woo-woo computer fix (thinking here of freezing HDD with seized bearings, or the half arsed attempts at reflowing GPUs) will be annealing ceramic caps ? bake your ram sticks at 170 degrees for 2 hours?

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 25, 2024, 07:59:50 am
content: "Bake until you see the plastic and epoxy parts start to change color. They're actually designed to do so, but the Industry Cabal has kept it secret to increase computer sales and reduce repairs."

author: nctnico
author_rank: Super Contributor
timestamp: September 25, 2024, 01:18:45 pm
content: Quote from: Nominal Animal on September 25, 2024, 07:27:31 amIt is a physics limit: electrical loading of the signal lines which degrades signal integrity to a point where it is no longer reliable when two memory modules are connected in parallel. You have to keep in mind that memory with a 5600 speed grade needs a 5.6GHz+ bandwidth on the signals. It is a miracle a -from an RF point of view- ultra crappy connector like a DIMM slot can be pushed to supports these kind of frequencies. The problem really is in the connector system used for traditional memory slots like DIMM. A CAMM module does not have this limitation as the memory can be connected in parallel on the module itself while retaining excellent signal integrity.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 25, 2024, 01:45:03 pm
content: Quote from: nctnico on September 25, 2024, 01:18:45 pmYou forget: the example MB and processor supports 7600 MHz when using one full channel, two DIMM modules in the exact same connector.It has been extremely typical for the maximum DIMM clock for four modules to be a quarter less than for two modules. Much less when using ECC memory, of course. This was just an example of the "quirks" in current Intel/AMD memory controllers, though.Consider the phase space –– multidimensional region or regions where each axis is one of the properties like clock frequency, voltage, current, bus capacitive loading, and so on –– of each individual DIMM module. Each has their own error-free region, and that region tends to shrink as the related components (here, those on the motherboard) age, even if just by a few percentage points. Even if we ignore the interactions between the memory channels, it is the intersection of all DIMM modules' error-free region we need to operate in. It is is obvious that as we increase the number of modules, the intersection region shrinks, and that individual differences in DIMMs can make the difference between reliable and unreliable configurations even when using ostensibly identical modules.