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Old January 27th 21, 12:22 AM posted to alt.comp.hardware,alt.comp.os.windows-10
Paul[_28_]
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Posts: 1,467
Default RAN 1.35v vs 1.5v

micky wrote:
I wanted to get more RAM for my newly-acquired PC

Entering the make and model, HP EliteDesk 800 G1 Small Form Factor

Crucial suggests only CT2K102464BD160B

DDR3 PC3-12800 • CL=11 • Unbuffered • NON-ECC • DDR3-1600 • 1.35V •
1024Meg x 64 • $76 even cheaper at NewEgg,


Kingston suggests only KCP316ND8/8

Specs: DDR3, 1600MHz, Non-ECC, CL11, X8, 1.5V, Unbuffered, DIMM,
240-pin, 2R, 4Gbit $98


The items are in different order but the main difference seems to me to
be 1.35v vs 1.5v.

That seems important, right? How can they be different for the same
computer? (I'm not really concerned about price unless they could sell
it cheaper by making it at the wrong, lower voltage. )

Do I need to look up what the computer puts out? Would one of these be
overclocked if the computer puts out 1.5v and the other underclocked if
the computer puts out 1.35?

I already have 2 sticks, Do I want to get the same voltage that they
use, whatever that is?


------

Other differences are
Crucial says PC3-12800 but Kingston doesn't include that.

Kingston says X8, 2R, 4Gbit but Crucial doesn't include any of that.

Does any of that matter?


------

FTR, I only looked at Newegg because Crucial was out of stock. NewEgg
says "Ships from China. Newegg Most customers receive within 10-32
days."

Hmm. At
https://www.newegg.com/crucial-16gb-...82E16820156047
it says sold and shipped by Ram-Store and when you click on 12 New from
$88.46 , it goes to the bottom of the page where they have 12 vendors
selling the same thing. Just like Amazon does it. I only looked at the
first 5 but one is in Hong Kong and "Most customers receive within 4-17
days.". One is in the US and "Most customers receive within 7-9 days",
all except Hong Kong for the same price!! (For Hong Kong and the next 7
the price gets higher.)

But this doesn't matter until I understand the voltage question.


1.35V DIMMs run in a 1.5V motherboard.

There should be a FAQ with the details around somewhere.

https://superuser.com/questions/5641...y-or-overclock

The opposite would not work. There would be some AMD motherboards,
where the board spec will say "DDR3L only". If you ran a 1.5V
DIMM in a 1.35V motherboard, the memory would have errors but
nothing would burn.

Yours is more likely to be a 1.5V and runs either,

*******

The HP page says it supports 8GB modules. For least risk then,
we'd want those to be "2R" double sided ones. That's because it
is possible to make single sided 8GB modules, but that would not
necessarily be a good choice for this upgrade. (High density
modules, sometimes half the memory is not detected.)

1600-MHz DDR3 SDRAM; (4) DIMM slots enabling up to 32GB

When you buy Crucial, they're pretty good at working that out.

Kingston are on my less-trustworthy list now, because
they screwed over a poster by shipping single sided
DIMMs when the datasheet said the product would be
double sided. Once a company does that, their rep
becomes ****.

*******

There's more I could write, but so much speculation is
involved, I'll quit while I'm ahead :-)

You really want that Crucial, because it's "ordinary"
and does not involve guesswork. The problem is, business
machines like that HP, the BIOS is "dumb as a post"
and is part of the problem rather than the solution.

You should run CPU-Z (portable edition will do), and
double check the "current running conditions" table,
as well as the SPD table (possible conditions). Just
to see whether the HP is even able to make the best
out of what you're running for RAM right now. If your
machine is a "sloppy jalopy", it'll be running the
1600 RAM at 1333, just because it's stoopid.

Most of my speculation problems involve not being
able to verify a candidate RAM is double sided. I don't
want you having to ship the RAM back because it is
only "half-detected".

This is an example of the level of detail available for RAM.
If CPUZ had done this (rather than the BIOS level test the
reviewer did), the table would have five lines. Three regular
and two XMP ones. Three other lines in the table are done
by the BIOS "via interpolation". There's no sign the table
in this one stops at 666 MHz on regular entries, so just maybe
there would be a happy ending in the HP machine.

https://www.hardwareluxx.de/communit...eil-3.1028883/

G.SKILL ARES F3-2133C9D-8GAB​

Profile CL RCD RP RAS RC RFC CR RRD WR WTR RTP FAW WCL Vdimm
457 MHz 6 6 6 16 22 74 - 3 7 4 4 14 - 1.50V
533 MHz 7 7 7 19 26 86 - 4 8 4 4 16 - 1.50V
609 MHz 8 8 8 22 30 98 - 4 10 5 5 19 - 1.50V
685 MHz 9 9 9 24 33 110 - 5 11 6 6 21 - 1.50V
761 MHz 10 10 10 27 37 122 - 5 12 6 6 23 - 1.50V
800 MHz 11 11 11 28 39 128 - 5 12 6 6 24 - 1.50V
XMP #1 (DDR3-2133) 9 11 10 28 38 171 2 6 16 9 9 27 7 1.65V
XMP #2 (DDR3-2133) 9 11 10 28 38 171 2 6 16 8 8 27 7 1.65V

XMP has the ability to set the voltage as well as the timing,
and XMP is "automatic overclocking", taking a lot of the
guesswork out of the picture. But one of the problems
with it, is if you have a four slot machine, with four DIMMs,
the XMP setting does not apply. Only a few DIMMs have a four DIMM XMP
config, because by definition, "fully loaded buses don't come
with guarantees", and the manufacturer would need a lot of
test margin to be offering such. And at least some DIMMs,
don't have a lot of margin to begin with.

Good luck in the hunt, Obiwan.

Paul