[SOLVED] 3200 Ram doesn't boot on first channel.

[coffinjoe]

Really wierd issue thats bothering me, i recently purchased a Vengeance pro rgb 3200mhz 2x8 kit. When i install the kit on the first channel A1 - B1. The pc fails to boot with XMP. When i put the kit on Channel A2-B2 the pc boots fine with XMP on, everything fine, can pass prime95 ram stress with no sweat. Why can't i boot on the first channel with this kit? is there something wrong with MB? My old kit with 2x8 3000mhz from corsair boots fine on the first channel.

Specs: 8700K @4.8 on a Asrock Z370 Gaming K6, latest bios. tried cmos and issue still persists, if i lower the frequency to 3000mhz the pc boots fine on first channel. Is there any downside to using the second channel?

 

[Darkbreeze]

Those are the wrong slots. EVERY, EEEVERY, dual channel motherboard made for AT LEAST the last ten years, specifically designates the A2 and B2 slots, which are the second and fourth slots over from the CPU socket, for two DIMM population. Move them to those slots, and if JUST doing that doesn't do the trick, then do a hard reset of the BIOS to clear the hardware tables and it should work fine.

The problem is there are two different KINDS of channels that they are talking about in most motherboard manuals. For dual channel operation AND for complying with the population guidelines, you need to have them in the A2 and B2 slots. If you put them in those slots and then check the memory tab in CPU-Z, you will see that in the "channels" field it will say "dual". That is normal and correct.

The primary "channel" is A2 and B2. The secondary channel is A1 and B1. For ALL dual channel boards. No exceptions.

BIOS Hard Reset procedure

Power off the unit, switch the PSU off and unplug the PSU cord from either the wall or the power supply.

Remove the motherboard CMOS battery for five minutes. In some cases it may be necessary to remove the graphics card to access the CMOS battery.

During that five minutes, press the power button on the case for 30 seconds. After the five minutes is up, reinstall the CMOS battery making sure to insert it with the correct side up just as it came out.

If you had to remove the graphics card you can now reinstall it, but remember to reconnect your power cables if there were any attached to it as well as your display cable.

Now, plug the power supply cable back in, switch the PSU back on and power up the system. It should display the POST screen and the options to enter CMOS/BIOS setup. Enter the bios setup program and reconfigure the boot settings for either the Windows boot manager or for legacy systems, the drive your OS is installed on if necessary.

Save settings and exit. If the system will POST and boot then you can move forward from there including going back into the bios and configuring any other custom settings you may need to configure such as Memory XMP profile settings, custom fan profile settings or other specific settings you may have previously had configured that were wiped out by resetting the CMOS.

In some cases it may be necessary when you go into the BIOS after a reset, to load the Optimal default or Default values and then save settings, to actually get the hardware tables to reset in the boot manager.

 

[coffinjoe]

OMG, you are totally right, just looked into manual and it indeed says it needs to be on A2-B2. So the ram is working fine then, thank you so much, i was so worried! Im such a noob, wow!

 

[Darkbreeze]

Im such a noob, wow!

Not really. I've seen a number of experienced builders get confused by the way this can be presented in some motherboard manuals. It's misleading and I've sent requests to a few manufacturers asking for corrections in the wording that is found in the memory sections. Of course, they don't care what I say, and are unlikely to change it since the population rules are generally accurate even if there are notations that are confusing and contradictory, or seemingly so.

Just keep it in mind for the future. If it is a dual channel motherboard, it is, so far anyhow, always going to be the A2 and B2 slots if the board has four DIMM slots and you are installing two DIMMs. For triple, quad, six or octa channel boards, that likely doesn't apply but those are generally HEDT high end, not consumer mainstream systems.