If you have some 1.65V memory, you could try it. I think you should stick with standard 1.5 Volt modules.
Dell computers are VERY picky about memory. Nobody knows why.
Some people even find certain brands do not work at all. Kingston brand for example is very risky, especially the "value ram". Nobody knows why they won't work.
Sometimes a dell computer cannot work with two different brands of memory which meet exactly the same specs yet will not work. Nobody knows why.
There are rockstars (high ranking) here who have dells that will not use two different brand name of memory which otherwise work fine. It is another secret dell mystery.
I've never tried 1.65V memory in my dell 790. I can say it works fine with standard 1.5V, 8GB modules. 2RX8. I think 1.35V modules will also work, since they conform to the ddr3 specs.
I would avoid 1.65V modules unless someone reports on them.
Why do you need to use 1.65V modules? If you have some in a junk box, give them a try.
there is no 1.65v DDR The 1.5v to 1.65v is the legal range for all 1.5V DDR, it is spec range, forget 1.65v. OK (muddies the waters)
the PC is in FACT 1.5v DRR SPEC CPU, the CPU dictates what it can run and is not modern 1.3v.
what matters is where you buy the ram. (NEW versus OLD)
old ram is 1.5v, back in i5-2400 days. and only this. back then.
DDR3 started in year 2007 your CPU was born in 2011, so your CPU is now 9 year old
the CPU designers in the year 2011 (2009-10 drawing boards) can not see the future can they? no, with newer 2020 DDR with super high density DRAM chip, so the limits are here, in your CPU datasheet clearly.
again your CPU, and again is 1.5v and again modern memory is ALL DUAL Volts, ask Crucial they tell you that.
device means Dram actual chips each. Gb is GigaBIT not byte. this is in the I5-2400 data sheet 1,
at intel.com and the logic is fixed, this is what we say when we say DENSITY LIMITS.
It is not like changing a light bulb, sorry, Intel sets rule 1 and DELL BIOS #2. ok/
max ram is 16GB on all but uSFF at 8GB.
min is 1GB. (max stick size is 4GB) 1,2 or 4, allowed.
what is raw card version rule (page 19_)
Desktop PCH platform DDR3 DIMM Modules—
Raw Card A – Single Ranked x8 unbuffered non-ECC—
Raw Card B – Dual Ranked x8 unbuffered non-ECC—
Raw Card C – Single Ranked x16 unbuffered non-ECC
this is not the first DDR3 post, ive done many and if you want to by RAM tell the helper what PC you have,
MT? DT, SFF, what? the MT has 4 slots do you >?
then what OS, non stated, so buying over 4GB is useless with 32bit OS.
and is tested at the upper 1.65v limit, as we all know can fail for heat, high voltage it runs hotter and to qualify the memory the do the whole legal range of voltages, (gee all chips are tested at all legit extremes)
it is the sellers that are confused, here, this is 1.5v stick for sure. and is spec, DDR3, (DDR3L is 1.3v)
new sticks are both, DDR3/DDRL3 now. all are. every one new is. end the panic unless buying old rare DDL3L
that SPD chip is the PnP chip that TELLS the PC what the STICK can do,, and is 1.5v. spec.
end 1.65v , endless misDIRECTION NOW> please.
WHAT MATTERS is DENSITY restrictions on GEN2 CPU!!!!
790MT, (I have one, and MT, and have tested vast types of ram in mine) most do fail. (this old now, lots do)
Chipset Q65 this CPU you HAVE gen 2, is in fact 1.5v, (1.65v is not a type at all it is the 1.5v upper limit)
IS THIS A PRE BUY question?
New or USED? from fleabay? where is your source ,even URL to it, helps. lacking photos of yours.
buy only from top sellers. Crucial or Kingston.
buy certified RAM, not generic, see why? (returns allowed on former) yah.
post the makers TAG data, , name , and full model, of the memory,
Memory is complex and is always limited at lest by the chipset rules and Dell BIOS rules
step 1 is to ungraded your bios so it might use more different memory,
rule #1 is matched sets, do not mix brands and types, or you get nowhere at all.
size , ranks, density ,maker , and number is chips per side and 1 or 2 sided sticks (AND MORE)
BIOS set what you can run the poor dell spec page shows. NO PC stated no slot count told.
Up to four DIMM slots; Non-ECC dual-channel 1333MHz DDR3 SDRAM, up to 16GB
NO OS stated by you, are you going to run 64bit OS to get over 3.5GB of RAM, tell that first. so we can make the best answer to you , OK>
the Processor in this PC runs the DDR RAM. directly and the limits are its rules and BIOS /Dell rules, not told. by dell,
Dell does not publish QVL , lists of tested RAM. OK like other great companies do.
let me guess, it is I5-2xxx CPU. gen 2, and uses GEN2, CPU rules for, DDR.
if you bought new DDR sticks they are all Dual voltage rated, that is a fact told by the top 3 sellers of Sticks (you can scan the SPD chip in the stick and see that)
the problems are old sticks, at a fixed voltage only, 1.65 is not correct its 1.5 to 1.65, (if you read the data sheet on it youd see that)
1.3v is modern/ and all modern sticks are now DUAL voltage (but not on old sticks.)
now I will quote intel off your CPU data sheet page, direct, (non Registered !)
System Memory Support• Two channels of unbuffered DDR3 memory with a maximum of two UDIMMs or SO-DIMMs (for AIO) per channel • Single-channel and dual-channel memory organization modes• Data burst length of eight for all memory organization modes• Memory DDR3 data transfer rates of 1066 MT/s and 1333 MT/s • 64-bit wide channels• DDR3 I/O Voltage of 1.5 V• The type of memory supported by the processor is dependent on the PCH SKU in the target platform— Desktop PCH platforms support non-ECC un-buffered DIMMs only— All In One platforms (AIO) support SO-DIMMs• Maximum memory bandwidth of 10.6 GB/s in single-channel mode or 21 GB/s in dual-channel mode assuming DDR3 1333 MT/s• 1Gb, 2Gb, and 4Gb DDR3 DRAM technologies are supported— Using 4Gb device technologies, the largest memory capacity possible is 32 GB, assuming Dual Channel Mode with four x8 dual ranked unbuffered DIMM memory configuration.
now PAGE 20 in your data sheet.
Back long ago, intel tested these DENSITY sticks and worked, this is based on MMC logic inside the CPU, and only this matters at this level of logic.
The other poster here does not know there are 3 stick types, old 1.5, old 1.35 and dual and vast type of density allowed, or not.
DENSITY is the big show stopper on all DDR3, and not upgrading BIOS>
Here, we have lots of woeful campfire tales about how picky dells are about memory brands. .eg. "my cousin found that xxx brand does not work in ANY dells, never ever"
Or, "only dell brand or crucial brand will ever work!"
BOO ............................ just kidding,, enjoy your new memory
moltoncore
8 Posts
0
January 25th, 2020 16:00
But will 1.65v memory be accepted... as well you say that this motherboard accepts 8gb modules?
donm4599x
2 Intern
•
478 Posts
0
January 25th, 2020 16:00
Use ddr3, 1.5V, or ddr3L, 1.35V memory. Single rank or dual rank. 8GB modules or less.
If you buy from crucial (brand name), and choose their recommendation, they will accept returns if it doesn't work. Otherwise you are on your own.
donm4599x
2 Intern
•
478 Posts
0
January 25th, 2020 16:00
@moltoncore
If you have some 1.65V memory, you could try it. I think you should stick with standard 1.5 Volt modules.
Dell computers are VERY picky about memory. Nobody knows why.
Some people even find certain brands do not work at all. Kingston brand for example is very risky, especially the "value ram". Nobody knows why they won't work.
Sometimes a dell computer cannot work with two different brands of memory which meet exactly the same specs yet will not work. Nobody knows why.
There are rockstars (high ranking) here who have dells that will not use two different brand name of memory which otherwise work fine. It is another secret dell mystery.
So, you must plug them in and see if they work.
It is a Dell Mystery.
donm4599x
2 Intern
•
478 Posts
0
January 25th, 2020 17:00
@moltoncore
I've never tried 1.65V memory in my dell 790. I can say it works fine with standard 1.5V, 8GB modules. 2RX8. I think 1.35V modules will also work, since they conform to the ddr3 specs.
I would avoid 1.65V modules unless someone reports on them.
Why do you need to use 1.65V modules? If you have some in a junk box, give them a try.
savvy2
3 Apprentice
•
2.5K Posts
0
January 26th, 2020 05:00
there is no 1.65v DDR
The 1.5v to 1.65v is the legal range for all 1.5V DDR, it is spec range, forget 1.65v. OK (muddies the waters)
the PC is in FACT 1.5v DRR SPEC CPU, the CPU dictates what it can run and is not modern 1.3v.
what matters is where you buy the ram. (NEW versus OLD)
old ram is 1.5v, back in i5-2400 days. and only this. back then.
DDR3 started in year 2007 your CPU was born in 2011, so your CPU is now 9 year old
the CPU designers in the year 2011 (2009-10 drawing boards) can not see the future can they? no, with newer 2020 DDR with super high density DRAM chip, so the limits are here, in your CPU datasheet clearly.
again your CPU, and again is 1.5v and again modern memory is ALL DUAL Volts, ask Crucial they tell you that.
device means Dram actual chips each. Gb is GigaBIT not byte. this is in the I5-2400 data sheet 1,
at intel.com and the logic is fixed, this is what we say when we say DENSITY LIMITS.
It is not like changing a light bulb, sorry, Intel sets rule 1 and DELL BIOS #2. ok/
max ram is 16GB on all but uSFF at 8GB.
min is 1GB. (max stick size is 4GB) 1,2 or 4, allowed.
what is raw card version rule (page 19_)
Desktop PCH platform DDR3 DIMM Modules—
Raw Card A – Single Ranked x8 unbuffered non-ECC—
Raw Card B – Dual Ranked x8 unbuffered non-ECC—
Raw Card C – Single Ranked x16 unbuffered non-ECC
this is not the first DDR3 post, ive done many and if you want to by RAM tell the helper what PC you have,
MT? DT, SFF, what? the MT has 4 slots do you >?
then what OS, non stated, so buying over 4GB is useless with 32bit OS.
savvy2
3 Apprentice
•
2.5K Posts
0
January 26th, 2020 05:00
I now see your 1.65volt confusions.
if I search for 1.65v , I find this.
Corsair Memory CMX4GX3M1A1600C9 1.65v (amazon confused)
well that same card at the makers site states clear as day , it is 1.5v SPD chip listed at 1.5v.
and is tested at the upper 1.65v limit, as we all know can fail for heat, high voltage it runs hotter and to qualify the memory the do the whole legal range of voltages, (gee all chips are tested at all legit extremes)
it is the sellers that are confused, here, this is 1.5v stick for sure. and is spec, DDR3, (DDR3L is 1.3v)
new sticks are both, DDR3/DDRL3 now. all are. every one new is. end the panic unless buying old rare DDL3L
that SPD chip is the PnP chip that TELLS the PC what the STICK can do,, and is 1.5v. spec.
end 1.65v , endless misDIRECTION NOW> please.
WHAT MATTERS is DENSITY restrictions on GEN2 CPU!!!!
savvy2
3 Apprentice
•
2.5K Posts
0
January 26th, 2020 05:00
790MT, (I have one, and MT, and have tested vast types of ram in mine) most do fail. (this old now, lots do)
Chipset Q65 this CPU you HAVE gen 2, is in fact 1.5v, (1.65v is not a type at all it is the 1.5v upper limit)
IS THIS A PRE BUY question?
New or USED? from fleabay? where is your source ,even URL to it, helps. lacking photos of yours.
buy only from top sellers. Crucial or Kingston.
buy certified RAM, not generic, see why? (returns allowed on former) yah.
post the makers TAG data, , name , and full model, of the memory,
Memory is complex and is always limited at lest by the chipset rules and Dell BIOS rules
step 1 is to ungraded your bios so it might use more different memory,
rule #1 is matched sets, do not mix brands and types, or you get nowhere at all.
size , ranks, density ,maker , and number is chips per side and 1 or 2 sided sticks (AND MORE)
BIOS set what you can run the poor dell spec page shows. NO PC stated no slot count told.
Up to four DIMM slots; Non-ECC dual-channel 1333MHz DDR3 SDRAM, up to 16GB
NO OS stated by you, are you going to run 64bit OS to get over 3.5GB of RAM, tell that first. so we can make the best answer to you , OK>
the Processor in this PC runs the DDR RAM. directly and the limits are its rules and BIOS /Dell rules, not told. by dell,
Dell does not publish QVL , lists of tested RAM. OK like other great companies do.
let me guess, it is I5-2xxx CPU. gen 2, and uses GEN2, CPU rules for, DDR.
if you bought new DDR sticks they are all Dual voltage rated, that is a fact told by the top 3 sellers of Sticks (you can scan the SPD chip in the stick and see that)
the problems are old sticks, at a fixed voltage only, 1.65 is not correct its 1.5 to 1.65, (if you read the data sheet on it youd see that)
1.3v is modern/ and all modern sticks are now DUAL voltage (but not on old sticks.)
now I will quote intel off your CPU data sheet page, direct, (non Registered !)
System Memory Support• Two channels of unbuffered DDR3 memory with a maximum of two UDIMMs or SO-DIMMs (for AIO) per channel • Single-channel and dual-channel memory organization modes• Data burst length of eight for all memory organization modes• Memory DDR3 data transfer rates of 1066 MT/s and 1333 MT/s • 64-bit wide channels• DDR3 I/O Voltage of 1.5 V• The type of memory supported by the processor is dependent on the PCH SKU in the target platform— Desktop PCH platforms support non-ECC un-buffered DIMMs only— All In One platforms (AIO) support SO-DIMMs• Maximum memory bandwidth of 10.6 GB/s in single-channel mode or 21 GB/s in dual-channel mode assuming DDR3 1333 MT/s• 1Gb, 2Gb, and 4Gb DDR3 DRAM technologies are supported— Using 4Gb device technologies, the largest memory capacity possible is 32 GB, assuming Dual Channel Mode with four x8 dual ranked unbuffered DIMM memory configuration.
now PAGE 20 in your data sheet.
Back long ago, intel tested these DENSITY sticks and worked, this is based on MMC logic inside the CPU, and only this matters at this level of logic.
The other poster here does not know there are 3 stick types, old 1.5, old 1.35 and dual and vast type of density allowed, or not.
DENSITY is the big show stopper on all DDR3, and not upgrading BIOS>
savvy2
3 Apprentice
•
2.5K Posts
0
January 26th, 2020 06:00
the 790 tricks are here, with lots of tests and how it all works.
your worries are justified, after reading the Manual
Missing now on Dell.com web site is this greater DELL™ OPTIPLEX™ 790 TECHNICAL GUIDEBOOK - V 2.0, page 19
but in REALITY (a horse of different color) IT DOES WORK.
and ddr3 (hv) can be a pain. to find and match up 2 sets or worse 4.
savvy2
3 Apprentice
•
2.5K Posts
0
January 26th, 2020 06:00
moltoncore
8 Posts
1
February 1st, 2020 08:00
I am using the Patriot 1.65v modules and they work fine. thx all
donm4599x
2 Intern
•
478 Posts
0
February 1st, 2020 14:00
@moltoncore
Oh my goodness... That's blasphemy! Kingston? It never works in dells. Shame on you! Only crucial.
I'm covering my ears, so I won't hear you any more.
moltoncore
8 Posts
1
February 1st, 2020 14:00
Just for the record: PGV38G1333ELK
edit: as well, I ran this module for a while as well:
Kingston KTL-TC316S/4g
donm4599x
2 Intern
•
478 Posts
0
February 1st, 2020 14:00
@moltoncore
GREAT!
And thanks for the feedback.
Here, we have lots of woeful campfire tales about how picky dells are about memory brands. .eg. "my cousin found that xxx brand does not work in ANY dells, never ever"
Or, "only dell brand or crucial brand will ever work!"
BOO ............................ just kidding,, enjoy your new memory