memory voltage

[Jaskanwar Singh]

guys see this for example -

Kingston 2GB Desktop Memory KVR800D2N6

*www.primeabgb.com/index.php?page=s...tegory_id=137&option=com_virtuemart&Itemid=53

*www.primeabgb.com/index.php?page=s...tegory_id=172&option=com_virtuemart&Itemid=53

Gskill Ripjaws 1333 DDR3 4GB Kit

kingston is labeled as 1.8v, corsair and ocz as 1.65v and g.skill as 1.5v. how does this make a difference. do motherboards support all of these.

BTW ddr3 memory prices are so low now
*www.primeabgb.com/index.php?page=s...tegory_id=137&option=com_virtuemart&Itemid=53

 

[coderunknown]

some are for Core i*. they need low voltage memory. AMD platform mayn't support them.

 

[pulkitpopli2004]

well yeah each mobo supports only particular memory voltage...
till nw as i have seen.. evry mobo was given with 1 JEDEC standard voltage which is usually 1.5V and overvoltage which was 1.60V and 1.65V.. dis was in case of P55 mobo(which i saw)..
in LGA775 package supported volg is 1.8V..
in Q57 it was 1.2 to 1.7V

 

[SlashDK]

AMD does support that low voltage one. Check my rig in my signature.

 

[Power_user_EX]

guys see this for example -

Kingston 2GB Desktop Memory KVR800D2N6

Products

OCZ Gold Series DDR3 PC3-10666 4GB

Gskill Ripjaws 1333 DDR3 4GB Kit

kingston is labeled as 1.8v, corsair and ocz as 1.65v and g.skill as 1.5v. how does this make a difference. do motherboards support all of these.

BTW ddr3 memory prices are so low now
Corsair 2GB 1333 MHz DDR3 RAM VS2GB1333D3

The voltages depend on the DDR technology ... as specified by jedec

for DDR1 it was 2.3V (i don;t remember clearly)
for DDR2 its 1.8V
for DDR3 its 1.65V


All new generations rams have customs profile viz.. EPP , etc.. a.k.a extended profiles along with default stored in an SPD chip.

Custom Memory Voltages/Timings will be applied if the BIOS has no probs in applying the setting read from the spd chip or you it will be set to defaults given by jedec.

In that case u have to manually set the rated voltage in BIOS.

Like in my case i have 2x2Gb corsair DHX sticks rated at 4-4-4-12 @ 2.1v @ 800Mhz but when i leave it to the bios it discards the EPP profile and applies defaults viz.. 5-5-5-18 @ 1.8 so i have to manually set the timings and voltages.

well yeah each mobo supports only particular memory voltage...
till nw as i have seen.. evry mobo was given with 1 JEDEC standard voltage which is usually 1.5V and overvoltage which was 1.60V and 1.65V.. dis was in case of P55 mobo(which i saw)..
in LGA775 package supported volg is 1.8V..
in Q57 it was 1.2 to 1.7V

aaaaahh sorry dude but u r wrong imo... coz memory volts is decided by the memory controller on the northbridge/CPU or by the DDR version.

for DDR2 jedec specified 1.8V as standard / ref
for DDR3 jedec has specified 1.65V as standard / ref

even if LGA775 mobo has DDR3 slots then that mobo has to supply the sticks with jedec standard voltages i.e ~ 1.65V

Bottom line the voltages are decided by DDRx !!!

BTW u can change the voltages if ur BIOS supports... hence each mobo doesn't support particular mem volts but a range of volts depending which DDRx it supports

 

[asingh]

Best rule of thumb is to see if your board supports the:

1. The type of RAM.
2. The speed of the RAM.

Basically this will cover the mechanical and electronic fitment of the DIMMs to the motherboard. Now most RAM have two settings JEDEC and EPP. Voltage requirements for the latter would be higher, and the RAM does not operate on this level out-of-the-box. This is where OC comes into play. JEDEC will run on the board if it qualifies (1) and (2) from above.