RAM/Memory compatibility advice!

[Kesh6970]

Ok so I have a system, the components we're concerned with are:

• 
  

  i5 2500K (either not Oc'd or Oc'd very little)

  
  
  
• 
  

  2 x 4gb Corsair XMS3, 1333MHz, CL9, 1.5v RAM

  
  
  
• 
  

  ASUS P8Z77-V LX Motherboard

  
  
  

I'm looking to invest in more RAM (2 x 8gb sticks of Vengeance Pro, 2400MHz, CL11, 1.65v, to be precise ( link ).

My question is about compatibility between the 2 memory kits.

Could I potentially 'under-clock' the Vengeance kit to run at 1.5v, 1333Mhz and with a CL9 latency?

This config should be relatively straightforward to set in the BIOS, but what other metrics must I change? (I've spoken to a Corsair rep and he told me I'd need to tinker a little) I know there are drawbacks to this approach...such as only running at 1333MHz for the foreseeable future...BUT I don't have the budget to splurge on a brand new kit of 32gb, and at this point, capacity is a bigger necessity than speed (for Uni programming and research).

And also, (if everything else is successful), what applications would you wonderful folks recommend to test the compatibility (I'm thinking a few passes of Memtest, and a few hours on a RAM stress-test?)

Any advice on this topic would be greatly appreciated!

Thanks in advance

 

[Belgarathian]

Your motherboard supports DDR3 RAM up to 1600Mhz without an OC, so the Vengeance Pro may not be compatible (even though the MB supports 2400Mhz as an overclock. If it works, the system may be unstable). 

 

If you get the system to run, bed the system in with a stress test and memtest for a couple of hours. People say 24-48 hours is a good burn in, but realistically once the system gets up to temp if it's stable for 1-2 hours after this point you should be fine. 

[MageTank]

 

Ok so I have a system, the components we're concerned with are:

• i5 2500K (either not Oc'd or Oc'd very little)

• 2 x 4gb Corsair XMS3, 1333MHz, CL9, 1.5v RAM

• ASUS P8Z77-V LX Motherboard

I'm looking to invest in more RAM (2 x 8gb sticks of Vengeance Pro, 2400MHz, CL11, 1.65v, to be precise ( link ).

My question is about compatibility between the 2 memory kits.

Could I potentially 'under-clock' the Vengeance kit to run at 1.5v, 1333Mhz and with a CL9 latency?

This config should be relatively straightforward to set in the BIOS, but what other metrics must I change? (I've spoken to a Corsair rep and he told me I'd need to tinker a little) I know there are drawbacks to this approach...such as only running at 1333MHz for the foreseeable future...BUT I don't have the budget to splurge on a brand new kit of 32gb, and at this point, capacity is a bigger necessity than speed (for Uni programming and research).

And also, (if everything else is successful), what applications would you wonderful folks recommend to test the compatibility (I'm thinking a few passes of Memtest, and a few hours on a RAM stress-test?)

Any advice on this topic would be greatly appreciated!

Thanks in advance

 

Yes, every kit can be underclocked to a JEDEC standard. All kits have to be able to run at a standardized SPD configuration. Your board should auto-train the rest, so i doubt manual configurations will be necessary. Dial in the voltage at 1.5, dial the timings in at 9-9-9-24-CR2 (You might be able to get away with CR1, but JEDEC standard is 2n).

 

The rest should train itself to comply. Let me know if you have any issues after doing so.

[Kesh6970]

@MageTank I'm a bit of a tinker-noob, so if I throw the new RAM in the 2 available DIMMs, and then go to the RAM config page on the BIOS and change the settings you've stated (timing and voltage only), the CPU IMC will take control of the rest?

 

@Belgarathian I saw that my motherboard only has a few 2400MHz kits on it's QVL, I just assumed that was because it is a relatively old motherboard and not all ram kits will have been tested on it. I don't think my CPU is OC'd, if this is the case will the system just straight up not POST once I power it up? Will I be forced to overclock the system just for hte sake of adding RAM which will then be underclocked?

[MageTank]

@MageTank I'm a bit of a tinker-noob, so if I throw the new RAM in the 2 available DIMMs, and then go to the RAM config page on the BIOS and change the settings you've stated (timing and voltage only), the CPU IMC will take control of the rest?

 

@Belgarathian I saw that my motherboard only has a few 2400MHz kits on it's QVL, I just assumed that was because it is a relatively old motherboard and not all ram kits will have been tested on it. I don't think my CPU is OC'd, if this is the case will the system just straight up not POST once I power it up? Will I be forced to overclock the system just for hte sake of adding RAM which will then be underclocked?

Yes, the board will train the rest of the timings. It might cycle a few times, this is normal, but it will eventually boot within JEDEC standards.