Corsair Vengence DDR5 6600 only runs at 4800

[VRR]

I have 128GB of Vengence DDR5 6600 (4x32GB) installed in an Asus z790 Maximus Extreme motherboard. With XMP off, it runs okay at 4800, but no faster. If I turn on XMP, I see all the correct specifications (6600 plus the right timings), but the system will not boot. 

Any idea what I might try to get the memory running at its advertised speeds?

[LeDoyen]

AFAIK Corsair doesn't have a 128gb kit so it's probably two kits of 64? The advertised speed is when running the kits as they ship, two sticks only. on a 13900 KS it'd run fine i imagine.

The overclocking capability of the memory controller drops with the number of sticks used. It's unlikely you'd be able to run 4 dual rank sticks at 6600 without extensive manual tweaking, if it even manages to work at all.

Another user in the forum managed to have such configuration work at 5200 if i remember well (loading the XMP profile, then dropping the speed in the bios).

[VRR]

Thanks for the quick reply - and yes, I have 2 x 64GB kits installed (that is, a total of four 32G sticks). 

As a test, I'll try with only 64GB installed and see how it performs. After that, I guess I'll just use the settings from the XMP profile as a start and see what I can achieve by gradually changing the settings till I get something optimal. 

[LeDoyen]

make sure you use the two sticks from a same kit, and install them on motherboards slots A2 and B2.

My money is on a flawless boot at 6600.

But to be honest, the performance gains on 13th gen from high memory speed are anecdotic at best, at least for gaming. For your use case, you'll have to see if your main application favors bandwidth or capacity

[Tribandz]

I'm having the same issue where you able to resolve yours? I'm only running one kit 64gb(2x32) advertised at 6600. As soon as I turn on a-xmp it blue screens windows 11 on boot with a variety of different errors if I get it to boot again. My board an MSI MAG x670e tomahawk wifi rated for the speed. Turn off the a-xmp profile and works fine

[Martin.v.r]

SA voltage an Vccio2 look there 

[c-attack]

1 hour ago, Tribandz said:

I'm only running one kit 64gb(2x32) advertised at 6600. As soon as I turn on a-xmp it blue screens windows 11 on boot with a variety of different errors if I get it to boot again. My board an MSI MAG x670e

The original poster is on an Intel Z790 and that puts their RAM frequency range into a distinctly different category compared to AMD x670. 6000 is about the limit for simple plug and play with any kind of XMP preset. I am not sure if 6600 is possible at 2x32, but you will have to work pretty hard to get there. Look for a motherboard specific RAM overclocking thread in one of the usual Overclock or Reddit discussions. Individual settings will be largely cpu and motherboard specific.  When your turn off XMP the RAM is defaulting to its default 4800 frequency that all motherboards can run. You likely can find some ground in the middle between the 4800 baseline and the out of reach 6600, but you’ll need to manually configure it.