1600 o.c mother board - problems with 1600mhz ram stick

[tooplanx]

Hi,

I recently added another stick of 1600mhz 4GB DDR3 ram to my existing RAM of the same specs. It was only then that I realised that the RAM was only running at 1333Mhz. I then discovered that this was because my mobo supports 1333 / 1600 (o.c.). At this point my PC was booting and running fine.

After reading a bit about it all I went in to my BIOS and changed the RAM speed to 1600Mhz manually. I then tried to save and reboot, but the PC stopped at POST and wouldn't boot.

So I went about trying to reset the CMOS, both by using the jumper, and by removing the CMOS battery. This did nothing to help.

I then thought that perhaps my new RAM stick had gone bad, so I removed that and, HURRAH! the PC booted fine.

I then discovered two things:

- Firstly, resetting the CMOS had not been successful for some reason (I have no idea why, all power was removed).
- Secondly, and most importantly, if I changed the RAM speed back to 1333MHz in the BIOS, I could re-insert the new RAM stick and everything would work fine.

So:
Why will one RAM stick boot in 1600MHz mode but the other won't?

Thanks in advance!

P.S.

Here's my RAM details:

Slot #1
Type DDR3
Size 4096 MBytes
Manufacturer Hyundai Electronics
Max Bandwidth PC3-12800 (800 MHz)
Part Number HMT351U6CFR8C-PB
Serial Number 324311710
Week/year 35 / 12

Slot #2
Type DDR3
Size 4096 MBytes
Manufacturer Kingston
Max Bandwidth PC3-12800 (800 MHz)
Part Number ACR512X64D3U16C11G
Serial Number 1225927889
Week/year 27 / 12

All the timing values are identical.

 

[bitwright]

Check the specs for those sticks to see what voltages and timings they should be running at. My guess is that they weren't getting enough voltage to run at the OCed 1600MHz speed.

A quick search of the model numbers showed that both those sticks need 1.5v, though I think you might have listed the wrong part numbers, since one of the sticks I found was an SODIMM and the other a regular DIMM.

 

[skit75]

Try it @ 1.55V? Or do you have an XMP profile to try?

 

[tooplanx]

A quick search of the model numbers showed that both those sticks need 1.5v, though I think you might have listed the wrong part numbers, since one of the sticks I found was an SODIMM and the other a regular DIMM.

Hmmm.... those are what Speccy came up with

 

[tooplanx]

Try it @ 1.55V? Or do you have an XMP profile to try?

I've never done any real overclocking before, so I'm a bit ignorant of the technical aspects. I understand what you mean with the voltage, but what's an XMP profile?

Perhaps you could help clarify the process of overclocking for my situation:
- When using a 1600mhz stick in a 1600mhz (O.C) mobo, is this the same as overclocking any stick of RAM in any other motherboard, or is it (in theory) a much simpler process e.g. simply manually changing the speed?

Thanks for your help, both of you.

 

[skit75]

They keep the "O.C." part in the fog of war. Simply changing the frequency from 1333 to 1600 won't always suffice. The modules you have are rated at 1.5V but both should be OK to around 1.58V. You may need to boost the voltage for those modules to operate at 1600MHz on that motherboard. Start low at like 1.52 @ 1600MHz. and creep the voltage up until you get a POST then test in the OS for stability.

XMP is a template of settings in the BIOS(eXtreme Memory Profiles). These are preset voltages, frequencies and timings for the modules that the motherboard can work with. You may have an XMP for 1600MHz that you should try first. When you enable the XMP for 1600MHz, check the voltage on the RAM and make sure it isn't pushing more than 1.58V to the RAM. At least one of your sticks is not rated over this voltage.... i forget which one. Some go as high as 1.65V so watch out... be careful before you save & exit

 

[bitwright]

Try it @ 1.55V? Or do you have an XMP profile to try?

I've never done any real overclocking before, so I'm a bit ignorant of the technical aspects. I understand what you mean with the voltage, but what's an XMP profile?

Perhaps you could help clarify the process of overclocking for my situation:
- When using a 1600mhz stick in a 1600mhz (O.C) mobo, is this the same as overclocking any stick of RAM in any other motherboard, or is it (in theory) a much simpler process e.g. simply manually changing the speed?

Thanks for your help, both of you.

When running RAM at 1600MHz you are technically overclocking, hence the "(o.c.)" next to the 1600 in your mobo's specs. That being said, if you have ram that's been rated to run at that speed then you should be fine.

Whenever you overclock something you often have to increase the voltage running to that part in order to get it to run smoothly. XMP (eXtreme Memory Profile) is a standard data format that allows the RAM to tell your motherboard what settings to run it at, so that you don't have to set voltage and timing values yourself. In my experience XMP doesn't always work right. And in your case, where you are using two different sticks of RAM from different manufacturers, your sticks probably have different profile settings, which could be confusing the motherboard.

Open your case and get the brand and part number off of the sticker on your ram sticks. Look up the specs for those ram and see what voltages and timings you should be running them at, and then set those values manually in your mobo.

 

[tooplanx]

Thanks for both your replies.

I'll check to see if there is an XMP in the BIOS, but I didn't see any before.

I checked in CPU-Z and that gives the same RAM details. I'll open the case up and check the model number though at some point (I need to go to bed!).

I might try increasing the voltage as well then - does this have to be done for both sticks, or individually?

TBH, if it's going to get risky i might just leave it at 1333Mhz as I've heard there is very little noticeable performance difference between 1333 and 1600(?).

Thanks again to both of you. I'll update when I've got round to trying those things.

 

[skit75]

It can be risky sure. The voltage change will affect all RAM modules. And, yes, there is very little perceived difference between 1333MHz and 1600MHz in most real-world applications including games.