craycray:

I don't think it is running at 8400MHz. You see the big thing about DDR5 is that it is doubling data units per transfer over DDR4. So, it can run at half the frequency for the same amount of bandwidth. So 8400Mbps, is possibly running at 4200MHz but transferring twice as much.

This has been the same for years with DDR memory.. Honestly I was kinda hoping that maybe DDR5 would jump up to Quad Data Rate so for example DDR5-4000 would actually be running at a 1000Mhz clock. But seems like it's the same old Double Data Rate we've had for YEARS now! Graphics memory has gotten really weird as they still call it GDDR. The actual GDDR6 spec supports multiple clocking rates and there isn't any easy way to tell if it's using DDR, QDR or ODR rates. I bet we'll see some of the lower end video cards that use GDDR6 use QDR or even DDR rates if memory bandwidth isn't a huge concern. DDR (Double Data Rate) QDR (Quad Data Rate) ODR (Octa Data Rate) Like with the 2080Ti GDDR6 it's 14,000Mhz Effective and it's actually Octa-Data Rate (8x) and actually clocked at 1,750Mhz. But to not confused the hell out of people they typically still list it at DDR rates in most tools at 7000Mhz.

Shadowdane:

This has been the same for years with DDR memory.. Honestly I was kinda hoping that maybe DDR5 would jump up to Quad Data Rate so for example DDR5-4000 would actually be running at a 1000Mhz clock. But seems like it's the same old Double Data Rate we've had for YEARS now! Graphics memory has gotten really weird as they still call it GDDR. The actual GDDR6 spec supports multiple clocking rates and there isn't any easy way to tell if it's using DDR, QDR or ODR rates. I bet we'll see some of the lower end video cards that use GDDR6 use QDR or even DDR rates if memory bandwidth isn't a huge concern. DDR (Double Data Rate) QDR (Quad Data Rate) ODR (Octa Data Rate) Like with the 2080Ti GDDR6 it's 14,000Mhz Effective and it's actually Octa-Data Rate (8x) and actually clocked at 1,750Mhz. But to not confused the hell out of people they typically still list it at DDR rates in most tools at 7000Mhz.

Sorry, I suck at explaining things. What I was saying is that this doubling is on top of DDR4. This is because DDR5 essentially runs two channels per DIMM. So, if at a given clock you are getting XMBps on DDR4 per DIMM, you will get 2XMbps on DDR5 per DIMM at the same clock. So to your point, in certain ways this will give the benefits of QDR, without going to QDR. I hope this helps. EDIT: I will update my previous post to reflect that. Thanks for calling it out.