[CLASYS]

LLXX, on Jun 1 2006, 12:50 AM, said:

I don't believe RAM can age and become slower. They are, after all, only solid-state devices. There is nothing to "wear out", neglecting the effects of electromigration.

I have an XT 286 from the mid 1980s with original RAM, and it still works as it always did (the hard drive, however, is another story...)

You can keep your beliefs. I'll stick with the information from the chip manufacturers. Actually, you do have it somewhat right.

This is not a matter of "wearing out" as much as migration. The net effect is that undesirable capacitance builds up and the absolute maximum speed the chip could theoretically be accessed at becomes lower. Most of the effect occurs in the early years and mostly while the chip is powered on [as opposed to just lying around or being ambiently heated; however higher temperatures while powered on can exacerbate the situation, this is the basis of accellerated testing.]

Of course, if the SPD chip is limiting required access speeds to far slower than that, you never have a problem!

Back when my IBM PC II was new in the early '80's with original RAM, each motherboard was "burned in" with the entire board subjected to testing. As machines got newer, less testing was done. I suspect your XT 286 board was still using burned-in RAM that was thoroughly tested for ultimate [and lowered] speed, and then timed to match.

Back then, there was always some joker who thought that it was cool to set less wait states than the chips were marked for because "it worked". Of course it only ACTUALLY worked for some months! [The fix, of course, was to honor the RATED speed, not the casual observation speed!]

The sleezeballs from back then sold reject memory and people were duped into using it as if the markings could be trusted. These machines failed because the real speed of the memory was such that when new it barely passed, and as it aged, it went into unreliable territory at the claimed speed. In some machines, you could have wide lattitude on setting wait states to compensate, thus you got a slower machine but at least it worked. If the memory was that bad, then you were SOL for buying crap quality, etc.

Ever since we all switched to SDRAM with the little SPD chips on the memory board, all of this should be moot. But this doesn't stop Mr. three-letters and his brethren from making crap memory boards that claim the eventual speed to be the same as the when-new speed, and without a mobo that can compensate [and slow down] you are SOL with them when they age, etc.

cjl

[CLASYS]

03GrandAmGT, on Jun 1 2006, 01:23 AM, said:

Yeah, the little mice running in the ram don't get tired. My Amigas still run top notch the same as when I first purchased them. One still has the orig. HD that I installed in it. Maxtor 540 meg scsi 10+ years.
jd

Expected value. When chips aren't asked to do the ultimate impossible, they continue for centuries to do the possible.

Today memory isn't even unit-tested. All is done by statistics. Pull out a few random samples, subject them to accellerated testing [probably to the point of destruction!] and in essence find out the ultimate slowed-down access speed that can be reliably depended on when the chips are old.

Then test the entire lot merely for current access speed and basic functionality. Assume the entire lot will behave as compared to the samples subjected to the intense testing, perhaps with a tiny derating safety factor to hedge against the possibility that the samples weren't actually representative, but were perhaps a little "hotter" than the rest, etc.

Given the amount of powered-on hours on average we put computers to, an honestly rated system that has worked fine for three years should never have a RAM problem due to aging.

That said, the occasional cheater still comes up where the memory ages below the point of reliability. [Please note: I have already changed the RAM on several box-makers machines due to proven failure; none of them were as much as three years old. I guess the memory is rated to get past the warranty period and then crap out!]

In the world of laptops, there is a pervasive conventional wisdom about a quality point of "new memory" which of course begs the question as to how the original memory came to be known as "old memory". I had to help someone with a ThinkPad that was failing. The memory turned out to be from mr alphabet-soup instead of the original IBM [and it could have been and should have been an upgrade, but instead the original was removed and replaced with the third-party twice as large; this smells because if the original memory was present, the cost to upgrade to double memory should be less than replacing with the "new" one, etc.]. I suspect the eBay seller of this machine was creating a dichotomy of machines with IBM RAM culled off of such as this one, doubling up on IBM RAM on reliable models, and selling off the "new" memory machines for more memory because they were "better" etc.

cjl

[MDGx]

IMHO:
To my knowledge memory chips [any generation] do not "get old".
RAM components [even cheapo ones] are just electronic chipsets + copper/similar alloy PCB embedded wiring, they do not change configuration as time goes by.
Except for [as LLXX put it so well]...
EMI [electromagnetic interference]/ESD [electrostatic discharge]/EMP [electromagnetic pulse]
interference/discharges/pulses/fields which may sometimes damage/"kill" electronic components due to electromigration, but that is highly unlikely.
Such fields/discharges must be really strong and in close enough range to do real damage.

I've been building computers for over 10 years, and have seen ESD doing damage only once: killed a hard drive.
Although I've lost a few VHS tapes because I didn't pay attention, and placed them too near [< 3 feet (1 meter ~ 1 yard)] to my 18 inch (46 centimeters) woofer speakers.

Another example...
when you overclock your CPU/FSB/RAM/mobo/GPU/video/etc, in time overheating/improper cooling may "kill" certain silicon microcomponents due to electromigration.
But this process is also highly unlikely to happen in a short amount of time. Electromigration effects are usually seen after many years of usage.
Most of the time the user is unaware of such "micro-damage", and he/she may go ahead and upgrade/build/buy a new computer way before this happens at such extent, that is when the computer becomes unusable/unstable/unreliable.

HTH

This post has been edited by MDGx: 01 June 2006 - 04:19 PM

[CLASYS]

Not a p***ing contest, but I have been working on the hardware of computers since 1968, and PC's in particular since 1983.

Much of what MGDX says is true; he should listen to his own post.

The electromigration problem is exactly what "ages" the chips. It happens gradually over a period of months and years, assuming the ambient temperature is maintained in the usual manner within typical computer cases.

Moreover, it is totally predictable for any temperature and this principle is what is used to test RAM chips as they are made.

To ensure reliability, sample chips are tested using accelerated methods, which is just another way of saying they HEAT UP the chips, very similar to what overclocking does, as MGDX describes. The net effect is the same, namely a chip whose absolute access time is now longer/slower. The heat can be obtained by putting it into a temp-controlled oven, over-volting/over-clocking, or a combination of techniques. No matter how you get there, the chips are now "aged" essentially simulating the same effect that would happen over a larger course of time at more moderate temperatures.

Once "aged to perfection" by these methods, the access time to reliably get data from the chips is clearly worse than when it was new, sans electromigration that hasn't happened [yet]. Reputable memory makers use this ultimate access time to be programmed into the SPD chip on the DIMM module [including hopefully a little safety factor in case the tested chip is NOT quite representative of its batch-mates, since only samples are taken, NOT every chip!]. The result should be a memory module that will not ever fail in normal use for the foreseeable future. Hopefully this is what most of you see in your computers. As such, while the absolute access time [when NEW] far exceeds what is being required of it, as the chips age, the absolute access time is longer, but never so long as to tax what is demanded of it by the SPD chip, set to require merely the ultimate longer time due to the aging process, etc.

The problem is there are sleazy manufacturers, some with cutesy names with three letters in them, that violate the entire process. They buy what amounts to reject quality or marginal quality stuff that will NOT hold up with time. Simply put, the ultimate absolute access time violates the value programmed into the SPD chip, so eventually these crap parts WILL fail due to aging. They use parts that POSSIBLY could have been fine, had the SPD chip been programmed to properly account for the predictable degradation, but then some people would notice the slower performance from day one because the timing is now much slower than you would want.

Back in the "old days" [in the '80's], every board had wait-state jumpers to accomodate almost anything you could get for the boards. [Apparently few of you remember the boards with the multiple rows of chips which had capacities like 256K x 1 and 64K x 1. Yes, these are socketed chips with a total capacity of 64K for the small ones and 256K for the large ones. Do the math and see how many sockets it takes to FULLY populate a board out to a mighty 640K [the most memory ANYONE would ever need! Or so said IBM back then!] using a bunch of 256K chips to get to 512K bytes, and the 64K chips to get to 640K, etc.] For motherboards like that, you had to conservatively set the wait-state jumpers for the RATED memory speed, but there always was a joker or two who thought they could get "something for nothing" and just hand-waved settings that would get a faster machine that worked for a few months, only to have to set it to what was recommended in the first place in order for the machine to even work at all! Again, normal migration aging at work, etc.

And of course, there were some unscrupulous memory suppliers as well [not necessarily even having names, alphabet soup or otherwise!] selling essentially reject chips that BARELY worked as marked, only to age into total unreliability or even inability to even boot up, etc. Some were so bad that setting the absolute maximum wait-states couldn't make it work properly, such was the brazenness of selling junk, etc.

We went through a period of CPU counterfitting as well [I believe recently with regard to some AMD CPU's being mis/re-marked] back in the Pentium days. Essentially, P-75 was being passed off as a P-133 by removing Intel's speed rating silk-screen and replacing it with the bogus over-rating.

Some of the chips work perfectly fine as P-133, simply because, as new, migration hadn't set in yet. As the chip ages, it becomes impossible to use at that much of an overclock, and will work perfectly fine, but only as a P-75 as it REALLY originally was rated. [I once had one of these fakes in my hand. The subtle giveaway is that REAL Intel speed marking is done LATER and as such, the silk-screen never quite lines up with the rest of the markings on the chip; go look at any of the grey ceramic P chips [before the green ones]. But the counterfitters used bogus marking machines that ALWAYS lined up, etc.]

Electromigration is normal, expected, and can be dealt with. For the most part it is so. As such, most CPU's and memory don't ever see reliability problems, because the aging is built into the design. For the rest, you get fore-shortened product life as you are cheated. In a world with automatic SPD timing, it's easier to rip people off, and it is happening to a few, but just enough that you need to be aware of it.

cjl (using knowledge, experience, and facts, not intuition)

[erpdude8]

erpdude8, on Feb 14 2005, 05:39 PM, said:

horsecharles, on Feb 11 2005, 08:32 PM, said:

erpdude8... how do you rate MemTest86.... somewhere in between those 2?
<{POST_SNAPBACK}>

I did get a chance to test out MemTest-86 horsecharles. Pretty good. A little better than the MS Windows Memory Diagnostic tool. Not sure with RAMExam. The makers of RAMExam have a demo but the demo version is nearly worthless.

as for Fredledingue's question, the SP upgrade may support up to 2 Gb of RAM. Win95, 98 & ME can theoretically access up to 2 gigs of RAM and no higher than that.

Ah, that MemTest86 memory diagnostic tool is a major keeper. I've tested this tool on all my computers whether they have old or new memory chips. Kudos to horsecharles for introducting me to it.

[Bigbrit]

There is a later version of Memtest, it was re-written and is called Memtest86+.

I use this on ALL machines that show problems.

Download site is below, choose "Pre compiled booteable ISO"

http://www.memtest.org/#downiso

Also atached the file (really small and self booting)

Attached File(s)

•  memtest86__1.65.iso.zip (41.38K)
  Number of downloads: 22

[erpdude8]

THANKS, Bigbrit. Will check out Memtest86+ on try it out on all my computers.

MDGx, CLASYS and others should try this tool out to see if they have good or bad memory chips on their computers. I'd like to see some testimony from them about Memtest86+.

[erpdude8]

so guys, what do you think of CLASYS saying that all RAM "gets old" with age?

This post has been edited by erpdude8: 14 August 2006 - 04:17 PM

[jimmsta]

There's some truth to that statement. The silicon's electrical properties change over time, and as it seems, can become bad over time. This is why good ram can go bad. Age really cannot be used as a form of memory lifetime, as a system from 1998 could have been used for 3-4 hours a day, and have memory failure within a year, or a system from 1998, being used for 20-24 hours a day, for 8 years, with no failures. You can buy the cheapest RAM and get away with no problems, or you can purchase the most expensive RAM, and have it arrive DOA.

Electricity on silicon is a funny thing.

[erpdude8]

anyone else want to comment of what CLASYS said in his posts?

[RJARRRPCGP]

Quote

ALL MEMORY AGES AND GETS SLOWER. The circuitry of the memory is CAPABLE of dealing with the memory at its ultimate lower speed; reputable memory does this by not attempting to exploit the "extra" speed the memory has when it is "young". Because of the SPD chip and the way the memory is timed, this "extra" speed capability is not used. Thus, you have a smooth operation of memory that runs as you expect from day one and for years to come, etc.

Unfortunately there are disreputable memory chip vendors who sell memory sticks that emit bogus timing information that leads the mainboard to believe that the memory is capable of what ultimately it is not, namely reliable operation at the rated speed down the road. If the mainboard can be manually timed by ignoring the SPD information, you can indefinitely get the memory to run at WORSE than rated speed reliably, but you can only get the rated speed while the memory is "young" enough in terms of powered-on hours, etc.

That's incorrect. If the RAM couldn't handle the timings, it wouldn't just slow down, Windows or applications would start erroring. This isn't hard disk drives were talking about!

RAM isn't mechanical.

[erpdude8]

RJARRRPCGP, on Aug 19 2006, 04:11 PM, said:

That's incorrect. If the RAM couldn't handle the timings, it wouldn't just slow down, Windows or applications would start erroring. This isn't hard disk drives were talking about!

RAM isn't mechanical.

ahh, good point, RJARRRPCGP. the debate goes on whether or not RAM gets slower with age.

[MDGx]

erpdude8, on Aug 21 2006, 07:57 AM, said:

RJARRRPCGP, on Aug 19 2006, 04:11 PM, said:

That's incorrect. If the RAM couldn't handle the timings, it wouldn't just slow down, Windows or applications would start erroring. This isn't hard disk drives were talking about!

RAM isn't mechanical.

ahh, good point, RJARRRPCGP. the debate goes on whether or not RAM gets slower with age.

Exactly my point.
RAM does *not* slow down.
The only degradation that can happen within RAM chips occurs when electrons migrate, and in such cases, the user will experience errors booting, loading the OS/apps etc.

Thanks for the clarification.

[erpdude8]

MDGx, on Aug 21 2006, 01:43 PM, said:

erpdude8, on Aug 21 2006, 07:57 AM, said:

RJARRRPCGP, on Aug 19 2006, 04:11 PM, said:

That's incorrect. If the RAM couldn't handle the timings, it wouldn't just slow down, Windows or applications would start erroring. This isn't hard disk drives were talking about!

RAM isn't mechanical.

ahh, good point, RJARRRPCGP. the debate goes on whether or not RAM gets slower with age.

Exactly my point.
RAM does *not* slow down.
The only degradation that can happen within RAM chips occurs when electrons migrate, and in such cases, the user will experience errors booting, loading the OS/apps etc.

Thanks for the clarification.

wow, I'd like to see how CLASYS responds to this. not everyone will accept what he said of memory slowing down with age.

so MDGx, have you tested the MemTest86+ app yet?

[MDGx]

erpdude8, on Aug 22 2006, 09:38 AM, said:

so MDGx, have you tested the MemTest86+ app yet?

I have tested this tool a while back.
But I'll try it again in the near future, I know they have newer versions out.

Thanks.

[erpdude8]

I did read a post of mine saying I completely disagree on RAM slowing down with age in early 2005. do you think I was right all along, MDGx?

[MDGx]

As I said, RAM doesn't slow down, because the speed at which electrons travel within the silicon wafers + copper wiring/PCB remains always the same at the same environment temperature/pressure/humidity, unless you drastically decrease or increase ambient temperature.
Near absolute zero on the Kelvin scale [absolute zero K cannot be attained in the "real" world, it's only a "theoretical" value], electrons speed increases dramatically, which is what we like to call supraconductivity [also known as superconductivity].

But if RAM chips get [badly] deteriorated from electrostatic and/or (electro)magnetic discharges/fields, then operating/memory errors/lockups will likely ensue as a consequence.

There are many cases of slightly damaged RAM chips where normal operation is not disturbed, but it is likely that in time any further damage will surface as operating/memory errors/lockups.

Improper computer cooling may also lead to shortening RAM chips life, because increased temperature accelerates [as you well know] silicon microelectronic components damage, mainly through electromigration.

HTH

[Eck]

I think I need Geordi LaForge to translate this stuff for me. Electron's, Kelvin Scale's, ZeroG. Huh?

Guess that's what I get for majoring in Music.

Excuse the interruption.

[LLXX]

Besides physical damage, http://en.wikipedia....lectromigration is the largest cause of integrated circuit failures, especially in memory which has been overclocked/overvolted.

[randiroo76073]

So, basically, any mem stick can fail at any time[as can other components] depending on innumerable variables, how about underclocking - running pc 3200[400mhz] on a mobo set for pc 2700[333mhz], will this possibly extend life cycle?