RAM Channels Won't Run At Same Frquencies?

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FireDemon

Limp Gawd
Joined
Feb 10, 2006
Messages
256
Hey guys. Bit of an odd issue here that I don't ever remember encountering in all my days. Seeking advice.

I'm running an ASUS Crosshair V with an FX-8320 clocked stable at 4.875Ghz. I was also running 8GB of Crucial Vengeance PRO DDR2400, clocked to DDR2600 with a small voltage increase to 1.72v. Verified OCCT stable for 1 hour with large data set.

Today, I got 8GB more of the exact same RAM in the mail. When I say exact same, I mean from the seller, the same batch and out of the same machine. However, upon first installing the other two sticks, windows immediately crashes while loading. Obviously a sign that the RAM is not stable. Go into BIOS and downclock it from 2600 to 2300. Systems loads and operates fine. So, you would think that these two other sticks just can't clock quite as fast, right? Wrong!

I then decided to conduct a test and here's where it gets weird. I removed all the sticks, and installed the two NEW sticks that we're thinking are unstable at 2600 at this point, into the channel B slots (The slots I was running on only 8GB). I change the RAM speed back to 2600Mhz in the Bios and the system loads and runs fine. Uhm, OK. Next test, I take the two sticks that I KNOW for a fact are stable at 2600 and install them into the channel A slots. Windows crashes while attempting to load.

So at this point I know for a fact that all 4 sticks are 2600 stable. What's happening though is that whatever RAM you install will only run at these speeds if it is in channel B. If you leave the RAM divider set to 2600 and install anything into channel A, the system becomes highly unstable to the point that you're lucky to get into the bios and change it back. At DDR2300 speeds, the system is perfectly fine with all 4 slots occupied. And again just to clarify, it isn't an issue of QUANTITY because if I run only 2 sticks at a time, channel B all is good. Channel A no dice.

What gives? Do I need to increase RAM or NB voltage, or is this something else I'm looking at?
 
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UPDATE:

Looks like even at 2300 speeds, being able to boot into windows was only a minor improvement.

Was able to stream video for about an hour before the OS bluescreened. System idled fine all night but while preparing for work this morning, I decided to run Prime95 for a few minutes. All 8 threads immediately crashed within 10 seconds.

What the hell is going on here?
 
its much harder to oc with 4 sticks 'cause of the load on the controller. you cpu OC prob isn't as stable as you think it is. reset everything and start working your way back up with the four sticks in.
 
Just to clarify in case I worded it poorly, In the original post it states that using the channel corresponding with the black slots on the motherboard, the system is unstable with 2 sticks or 4. Any combination of sticks. It isn't an issue of 4 sticks, it's an issue of using the black DIMM slots on the motherboard. Using the red slots (Channel B), everything is OK.


Also I was doing some digging into the user manual. It says, "We recommend that you install memory modules in the red slots for better overclocking capability"

Anyone have insight on this?
 
try cleaning the slots and then see if you can get them running stock in the black slots.
the note in the manual is what I was saying about the 4 stick OC, most boards will only oc properly in two slot as the load from 4 is too much.
 
Like others have posted. Overclocking with all DIMMs filled isn't going to net the same results as overclocking with half of them.
 
Skillz said:
Like others have posted. Overclocking with all DIMMs filled isn't going to net the same results as overclocking with half of them.
Click to expand...

Please review post #4.

The problem isn't 4 DIMMs being occupied. Let me put it to you this way. 2 modules ONLY! Red DIMM slots, Everything OK. Black DIMM slots, system becomes unstable even at lower speeds. Why?
 
Skillz said:
Bad motherboard.
Click to expand...

I would agree and this was my thinking originally HOWEVER, one thing makes me wonder rather than be certain.

In the user manual for my motherboard, it states, "Please install DIMMs into the red slots for best overclocking ability".

Why is this? I contacted ASUS tech support and jesus that was like pulling teeth. Ended up hanging up on the guy.
 
If the system doesn't work or is unstable while all 4 DIMMs are populated with stock clocks then the motherboard is bad.

If you are overclocking, no matter how little and they're not working in the Black slots then RTFM. Don't overclock using the black DIMMs. It's really not rocket science man.
 
Skillz said:
If the system doesn't work or is unstable while all 4 DIMMs are populated with stock clocks then the motherboard is bad.

If you are overclocking, no matter how little and they're not working in the Black slots then RTFM. Don't overclock using the black DIMMs. It's really not rocket science man.
Click to expand...

OK. Since you seem to be so knowledgable, let me throw another variable in here. Board officially supports up to DDR2166 when overclocked. In the red slots, I am running at DDR2600 stable. Tried the black slots at DDR2300. Better, but still not stable. However, DDR2300 is still a hell of an overclock according to the official support, so I can try clock it slower and see what happens.

Here's that additional variable I mentioned however. From 2013 when I first built the system all the way up to a month ago, I was running FOUR Kingston HyperX 1866 modules clocked to 2145Mhz in ALL FOUR slots. Out of all that time, only last month did the RAM problem seem to surface. Tried reducing clock speeds to UNDER 2000Mhz and still no dice. I thought I had a bad stick so I decided to trade my 8GB kit in for the crucial memory I have now but the problem still persists.

I too am leaning towards a faulty RAM slot but again, the question that no one seems to be able to answer is exactly WHAT is the key difference between the red and black slots that makes the black slots undesirable!?
 
The red slots are probably identical to the black slots, but it's just so people don't populate all four slots at once and try to overclock. Then again, the red slots could have a better path to voltage. Most likely something so technical it's above all of our heads.

It's been a known thing for a long while that you'll get better overclocks using less DIMMs.

The board probably became faulty over time. These things happen.
 
Skillz said:
The red slots are probably identical to the black slots, but it's just so people don't populate all four slots at once and try to overclock. Then again, the red slots could have a better path to voltage. Most likely something so technical it's above all of our heads.

It's been a known thing for a long while that you'll get better overclocks using less DIMMs.

The board probably became faulty over time. These things happen.
Click to expand...

I agree. I've had it happen before.

The best place to post this is the ROG forum but I'm waiting for them to activate my account which won't happen until monday. I think my best option is to get a 2x8 kit of the same memory and simply resell my 4x4 kit. More hoops to jump through.
 
put them all in and set them to 2166, see how that goes. if its still unstable then the board is starting to die. the red slots are magic overclocking slots ;) idk its prob the wiring/trace paths in the mobo to allow better OCing in those slots.

edit: yes a 2x8 will be better
 
pendragon1 said:
put them all in and set them to 2166, see how that goes. if its still unstable then the board is starting to die. the red slots are magic overclocking slots ;) idk its prob the wiring/trace paths in the mobo to allow better OCing in those slots.
Click to expand...

LOL! Magical overclocking slots seem to be the best bet at this point.
 
One thing I'm beginning to wonder is if I'M not the one who killed the board over time, by running overclocked RAM in all 4 slots for 5 years.

But I can't definitively answer that until I know the key difference between red and black.
 
FireDemon said:
One thing I'm beginning to wonder is if I'M not the one who killed the board over time, by running overclocked RAM in all 4 slots for 5 years.

But I can't definitively answer that until I know the key difference between red and black.
Click to expand...
the blacks are prob limited to normal speeds, red specifically for OCing. might even be a voltage delivery thing...
 
pendragon1 said:
the blacks are prob limited to normal speeds, red specifically for OCing. might even be a voltage delivery thing...
Click to expand...

That would make sense. Either way, I just bought a 2x8 kit. If you know anyone interested in my 4x4 DDR2400 kit, I currently have a FS thread going.

The sticks are all fine. Its my board that's shoddy :(
 
FireDemon said:
....Board officially supports up to DDR2166 when overclocked. In the red slots, I am running at DDR2600 stable. Tried the black slots at DDR2300. Better, but still not stable. However, DDR2300 is still a hell of an overclock according to the official support, so I can try clock it slower and see what happens.
Click to expand...

FireDemon said:
...The sticks are all fine. Its my board that's shoddy :(
Click to expand...

Very odd definition of 'shoddy' imho! :p

But sounds like you have your solution either way. :cool:
 
spine said:
Very odd definition of 'shoddy' imho! :p

But sounds like you have your solution either way. :cool:
Click to expand...

Already got the 2x8 kit making its way across the country. Just need to unload the 4x4 kit and I'll be back to where I need to be.
 
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