X670E Users Get AMD EXPO Ultra Low Latency Support Via ASUS And MSI

It flew under the radar a bit, but one of the exciting announcements at Computex was AMD's new EXPO Ultra Low Latency standard for PC memory. This is, essentially, RAM that has been pre-qualified for operation at high speeds with relatively tight timings, which will improve gaming performance, especially on systems without 3D V-Cache. However, there was some concern that EXPO ULL support would require a next-generation motherboard. Fortunately, that turns out to not be the case.

We can say that with confidence because some motherboard vendors, notably ASUS and MSI, are already shipping BIOS updates for both current- and previous-generation Socket AM5 motherboards that enable the new feature. Videocardz points out that ASUS has added EXPO ULL support to many of its ROG Strix family X670E motherboards, although a few boards aren't quite ready yet. That site also mentions that MSI is publishing updates for X670E motherboards as well to implement support for the new memory profiles.

EXPO ULL isn't as simple as shipping EXPO profiles with tighter timings. It also exposes three new memory tuning values, "TccdL", "TccdL_WR" and "TccdL_WR2", which are interesting; the "ccd" here is "column to column delay," not anything to do with AMD's "CCD" (Core Complex Die). These values aren't strictly novel, but they haven't historically been exposed for tweakers to tune, so this is pretty exciting for those of us who enjoy fiddling with these values.


If you're wondering what the point of this is, it's mostly for gaming. While a faster CPU is always helpful, the overwhelming majority of video game workloads don't really care how fast your CPU is beyond a certain point. When we talk about a "CPU bottleneck" in gaming, what we're really talking about most of the time is actually a memory latency bottleneck, as the CPU is "busy" waiting on data from RAM. This is exactly why AMD's 3D V-Cache CPUs offer such a big benefit for gaming workloads, and it's also why fast memory helps notably less on those chips.

For the majority of folks who aren't so blessed to have the extra 64MB of L3 cache, including both non-X3D Ryzen users as well as Intel users, EXPO ULL memory could possibly offer significant gaming performance benefits. AMD claims you could get as much as 13% extra performance versus JEDEC memory on a Ryzen 7 9700X, although the benefit versus a standard EXPO kit is smaller, around 4%. But it's really the 1% lows where you're likely to feel this upgrade.

Hopefully the new EXPO ULL memory is actually available to buy soon. The consumer DDR5 market is a wasteland right now, with even mediocre memory kits going for upwards of $10/gigabyte—RAM pricing we haven't seen since the mid-2000s. While there are signs of cracks appearing in the AI bubble, memory vendors insist that this pricing problem is going to continue through 2028, so we'll just have to wait and see what happens.

_{Thanks to Videocardz for the spot!}