the tendency for motherboards to run RAM
at the low default base level clock speed
and high latency timings.
These profiles work by taking advantage of
the aforementioned Serial Presence Detect
chip that’s located on each stick of RAM. XMP
is simply an extension of the SPD standard,
which allows for memory manufacturers to
specify not just a safe minimal performance
level at which to run the module, but some
overclocked settings too.
You generally get two XMP profiles for
any given module. The first profile will be the
safe option that should give you the rated
performance figures you’ll see on the box.
The second profile will be a more extreme
version that may not be as stable.
In general, XMP offers an easy,
reasonably reliable way to ensure you’re
getting close to the most out of your
RAM. However, as we saw with thememory compatibility issues with the first
generation of Ryzen CPUs, there are other
factors at play, particularly as memory
controllers are now built into CPUs. This
applies doubly if you’re overclocking your
CPU. As such, it can be beneficial to take
control of setting your memory clock
speed and timings yourself, keeping a keen
eye on just which setting or level causes
your system to fall over.MEMORY DECOUPLING
One aspect that can further complicate
memory overclocking is that AMD Ryzen
systems enable you to decouple the
memory clock speed from the Infinity
Fabric clock speed. These two frequencies
are normally kept in lock step but, with
the fastest of RAM, it can be beneficial to
keep the Infinity Fabric running at a slower
clock speed and run the memory faster.
Moreover, you can even do the opposite,
using slower RAM but overclocking the
Infinity Fabric. If you compensate for
the slower clock speed of your RAM by
tightening the timings, this can result in
better performance in some applications.
Infinity Fabric decoupling is an
interesting tweaking option for peoplewho really want to experiment, but
we’ve seen few instances of this tweak
providing significant benefits outside of
extreme overclocking scenarios. For AMD
systems, opting for 3600MHz RAM with
the tightest timings possible, and sticking
to a 1:1 Infinity Fabric ratio, is the best route
to peak performance.THE FUTURE OF DRAM
The arrival of Intel Optane really set the cat
among the pigeons in terms of potentially
breaking the dichotomy of system memory
and long-term storage. However, it remains
too slow and expensive to truly be a viable
replacement for most desktop PCs. If Intel
can further improve speed and reduce costs,
however, we could certainly see it become
ever more commonplace in laptops, all-in-
ones and other small form factor PCs.
Then there’s DDR5, which has been
on the horizon for a while, but reportedly
won’t likely arrive until at least next year.
The doubling of data rates and lower
power consumption will certainly make
for an interesting potential step change in
performance, but it’s far enough off and
unproven enough that we wouldn’t hold
off on upgrading now because of it.Choosing an XMP profile is a reasonably reliable way of
setting up your DRAM for its intended performancethe tendency for motherboards to run RAM
at the low default base level clock speed
and high latency timings.
These profiles work by taking advantage of
the aforementioned Serial Presence Detect
chip that’s located on each stick of RAM. XMP
is simply an extension of the SPD standard,
which allows for memory manufacturers to
specify not just a safe minimal performance
level at which to run the module, but some
overclocked settings too.
You generally get two XMP profiles for
any given module. The first profile will be the
safe option that should give you the rated
performance figures you’ll see on the box.
The second profile will be a more extreme
version that may not be as stable.
In general, XMP offers an easy,
reasonably reliable way to ensure you’re
getting close to the most out of your
RAM. However, as we saw with the
memory compatibility issues with the first
generation of Ryzen CPUs, there are other
factors at play, particularly as memory
controllers are now built into CPUs. This
applies doubly if you’re overclocking your
CPU. As such, it can be beneficial to take
control of setting your memory clock
speed and timings yourself, keeping a keen
eye on just which setting or level causes
your system to fall over.MEMORY DECOUPLING
One aspect that can further complicate
memory overclocking is that AMD Ryzen
systems enable you to decouple the
memory clock speed from the Infinity
Fabric clock speed. These two frequencies
are normally kept in lock step but, with
the fastest of RAM, it can be beneficial to
keep the Infinity Fabric running at a slower
clock speed and run the memory faster.
Moreover, you can even do the opposite,
using slower RAM but overclocking the
Infinity Fabric. If you compensate for
the slower clock speed of your RAM by
tightening the timings, this can result in
better performance in some applications.
Infinity Fabric decoupling is an
interesting tweaking option for peoplewho really want to experiment, but
we’ve seen few instances of this tweak
providing significant benefits outside of
extreme overclocking scenarios. For AMD
systems, opting for 3600MHz RAM with
the tightest timings possible, and sticking
to a 1:1 Infinity Fabric ratio, is the best route
to peak performance.THE FUTURE OF DRAM
The arrival of Intel Optane really set the cat
among the pigeons in terms of potentially
breaking the dichotomy of system memory
and long-term storage. However, it remains
too slow and expensive to truly be a viable
replacement for most desktop PCs. If Intel
can further improve speed and reduce costs,
however, we could certainly see it become
ever more commonplace in laptops, all-in-
ones and other small form factor PCs.
Then there’s DDR5, which has been
on the horizon for a while, but reportedly
won’t likely arrive until at least next year.
The doubling of data rates and lower
power consumption will certainly make
for an interesting potential step change in
performance, but it’s far enough off and
unproven enough that we wouldn’t hold
off on upgrading now because of it.Choosing an XMP profile is a reasonably reliable way of
setting up your DRAM for its intended performance