On 5 Dec 2003 13:16:51 -0800,
(do_not_spam_me) wrote:


Then why did even cheaper K-byte and no-name Fry's memory work fine
that way? Some of the Fry's memory I've gotten has been really
questionable, but so far, all the DDR modules have tested OK.

Some may work fine because that's the situation with budget memory,
some of the chips are actually capable of higher, tigher timings than
others. It is only guaranteed to work at default SPD timings in a
motherboard conforming to spec as well. If the motherboard isn't
within spec, it may require higher quality memory... this is also a
known problem with ALL nForce2 boards.


It is incredible to me that you were trying to get Kingston to deal
with this. There is nothing wrong yet you're trying to get them to
upgrade your memory. Changing the timings is essentially
overclocking, something which no memory manufacturer guarantees.

It's incredible that you ignored what you quoted of my own message:

I tried all sorts of BIOS settings with both modules, but the
only thing that eliminated all the errors was slowing the memory bus
speed from 266MHz down to 200 MHz.

Sorry, I didn't draw a conclusion because "all sorts of" didn't tell
us anything specific. It could be that you just happened upon a bad
module... it happens, obviously it's not cost-effective for a
manufacturer to do as much testing on very cheap memory. On the other
hand, if the situation is reproducible with several modules it would
suggest a problem with the motherboard, since many many other people
use these modules without issue.

IOW I tried the _slowest_ settings as well, but the memory still
failed. I did try faster settings because I once had some PC133 CAS3
memory that wouldn't work in a VIA PC100 mobo except at CAS2, but this
also didn't help with the DDR.

Fair enough, it does sound like you did all the testing possible on
that board, but it doesn't rule out the board itself.


I'd never expect a manufacturer to be responsible for performance
beyond specs, but memory should work fine even at the BIOS' defaults,
and I'd insist on that because BIOS parameters are sometimes reset
automatically. I'm not an overclocker -- the fact that my fastest
computer is just an XP1800+ with a TNT2M64 card should indicate that,
and the only times I've even tried overclocking was while testing
memory, and that's only for curiousity (IOW if memory fails only while
overclocked, I don't consider it a real failure). My concern is only
about reliability.

Of the low-end modules, the ones I see with the least headroom for MHz
or timing increase are those with the cheaper PCB including film
resistors, not surface-mount parts, like this (thought it's of a PNY
PC2100 module):
http://69.36.189.159/usr_1034/pny-resistors.jpg

All the other Kingston PC2100 modules I've tried will do at least
166MHz @ 2.5,3,3,6 except for one that can only do ~ 145 or so,
providing only 1 or two modules are used. That is in multiple
motherboards of Via, Sis, and nForce chipsets.



you contacted Kingston did you specifically mention that you didn't
want to run the memory at it's spec'd speed, that it was only
producing errors when the timings were changed? What do you think
they would say to that?

I said that their memory failed even at the slowest settings unless
the bus was slowed to 200 MHz. They couldn't explain anything but
just gave the usual sales type excuses.

Unfortunately it's unlikely that you were speaking to anyone with
enough technical background to help unless they forwarded the call a
couple times, most likely you know a lot more about the issues than
whoever you were talking to.


The only memory modules that showed errors with these mobos were
K-byte with Spectec chips and later Kingstons. These are obviously
not prime memory modules because their chips are not labelled with the
chip manufacturer's standard part numbers but are either used or
second grade.

What were the numbers on the chips? I may have some, or a different
lot... all of those I have/had will do up to ~147Mhz, usually quite a
bit higher. I'm not surprised that they're not "prime" though, given
the low price. On the other hand I still think the motherboard is
playing a crucial role in the instability.


On my K7S5A Pro and P4S5A, the Luxons are only for bypass (green with
silver printing), and I don't think they're the low-ESR types, the
only ones affected by the Taiwan capacitor scandal. The low-ESR ones
in at least one of my ECS mobos are "Ost" brand, purple with gold
printing on them, but I don't know if they're involved in the scandal.
I took ESR measurements and found nothing, but I can't be sure the
measurements were valid because the capacitors may be in parallel.

The green-with-silver Luxons are "supposed" to be Low-ESR, they're
what's used in circuits clearly needing low-ESR caps, like for the
switching regulation of the CPU. I'm sure that at least one K7S5A
I've had, did have those green/silver Luxons there as well as around
the memory. I've seen Ost caps fail too, but not in large enough
numbers to draw a conclusion about 'em.

Well, actually I do recall having to replace about 9 of the
green/silver Luxons around the regulators on a K7S5A because they
vented... dead board... works fine now at 150MHz FSB with ??? (I
forget, some nearly FAR memory).


Millions of Kingston memory modules are sold, but only a few people
have problems... if it was the memory then you'd be hearing of a LOT
more reports of problems. What's the varible? Motherboard, number of
modules, BIOS settings.

Kingston is selling junk with unlabelled chips and can't even tell me
who's making their chips. Does that seem like a quality operation to
you?

The chips that say "Kingston" on them? I USED to know who made
those... time takes it's toll on my memory... might be Toshiba chips,
which have two circular mold marks near the center like this:
http://www.biwa.ne.jp/~yok/DDR-KIBAN...IBA75-OMO1.jpg


Most people don't test their memory thoroughly before putting it
to use, and in the case of one of the Kingston modules the errors
occurred only above the 220MB-240MB area, so it's possible that this
would rarely be used by Windows (but I don't know how Windows
allocates memory).

Don't know, maybe it's just a regoinal thing... the Kingston PC2100
modules in your region might be different than those here, which are
(on average) able to do a little over 170MHz... maybe higher but I've
only been using them on older boards with chipsets that aren't very
stable over 180MHz anyway, so i can't draw any conclusions above
170MHz.


Dave