Re: RAN 1.35v vs 1.5v

In alt.comp.hardware, on Tue, 26 Jan 2021 19:22:59 -0500, Paul
<[email protected]> wrote:

>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-240-pin-ddr3-sdram/p/N82E16820156047
>> 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/564175/1-35-v-ram-in-a-1-5-v-system-will-it-fry-or-overclock

First answer is:  As far as I know, the voltage of the board in the bios
shows the max voltage that can be drawn by the hardware, so if the RAM
only draws 1.35, that's all it should use. I'm not 100% though so this
is purely a comment, not an answer.

That's for sure, it's not an answer, because his first sentence shows he
doesn't know how electricity works.  <bg>

>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,

Great and that's confirmed below iiuc
>
>*******
>
>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.)

Oh, 2R. Okay!  The ones in there now are double sided, and I think I
should buy the same ones again. ??
>
>   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 shit.
>
>*******
>
>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

I used to have that, but didn't really get any particular use out of it.

But this time it's of very clear use. 

>double check the "current running conditions" table,

I can't find that table.  

>as well as the SPD table (possible conditions). Just

One thing the SPD tab shows is that Jedec 3-6 are all 1.5 volts.  I'm
looking for instructions.  Is that the voltage it expects or what it is
getting?  

https://tipsmake.com/instructions-for-using-cpuz-read-the-cpuz-parameters-provided

But it stops explaining before that line. 


******* At any rate, CPU-Z gives the maker and model of the RAM and I
think maybe I should just buy two more sticks of the same thing.  I
think someone here said having all 4 the same is good. 

I ran Memtest8? last night for 8 hours and it found no errors.    But
that just means the memory is good, iiuc, not that it is the right
memory.  ??

>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".

So with CPU. I found that I have now two SAMSUNG M378B1G73DB0-CK0 
which is out of stock several places but sdescribed on amazon as
    8GB 2RX8 PC3-12800U 

So buying the very same thing seems like a good idea, right?  

Still I'd like to know all its variables to make sure the refurbisher
didn't put the wrong thing in. But Samsung is not doing very well here.
This looks like the page for DDR3
https://www.samsung.com/semiconductor/dram/ddr3/ but it has no sticks
bigger than 4Gig.

Aha, I used the part numbers David posted and found that the remaining
parameters are correct: 

Voltage 1.5V
Rank	2Rx8
Cas Latency CL11


>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/community/threads/mini-user-review-g-skill-ares-f3-2133c9d-8gab-ein-p-l-tip-teil-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.

Tnank you, Captain. 
>
>    Paul