IN THE EARLY YEARS of commercial RAM,
before the turn of the century, there was
a serious disparity between CPUs and
memory. Referred to as the “memory
wall,” a problem arose where CPUs were
developing faster than RAM technology,
with RAM speed only increasing by
10 percent in the 14 years leading up to
2000, while CPU speeds increased by
approximately 55 percent. For a long time,
it looked like memory speed limitations
might cause a significant bottleneck in the
improvement of computer performance.
Since then, CPU speed increases have
slowed, due in part to physical design
barriers around heat dissipation and
die size in new chip designs. With the
improvement of caching tech to speed
up key processes and bridge the gap
between CPU and RAM speed, it looks
like the “memory wall” might be a fallacy.QWe’ve mentioned
that memory
specs have
different impacts
on Intel and AMD
processors. In
broad terms,
memory speed
hasn’t historically
made much
difference
to processor
performance, but
with AMD’s Ryzen
series of CPUs,
that norm changed
in a big way. Due
to conventional
processor
architecture, Intel
CPUs (currently
the Core series)
only see minimal
gains from
memory speed; a
couple of percent
at best in the
vast majority
of benchmark
functions.
With Ryzen,
though, AMD
did something
different: The
interface that
connects the
processor cores
together—called
the Infinity Fabric,
if you subscribe to
funky hardware
marketing
jargon—is
controlled from
the integrated
memory controller
on the chip. What
this means is thatwhen supported
by faster RAM, the
memory controller
can run faster,
and transfer
data between the
cores at higher
speeds, improving
overall processor
performance.
This was a
stumbling block
for Ryzen in
the early days,
because when the
processor line first
became available
in 2017, memory
was significantly
more expensive.
The effects of
memory speed on
Ryzen chips works
both ways: SlowerRAM can result in
poor performance
compared to
similar Intel Core
CPUs. As memory
has become
cheaper, though,
Team Red looks
more and more
attractive. A few
hundred additional
MT/s can make
a difference
in processor
performance of
10 percent or
more, which can
be pumped up
even higher when
combined with
CPU overclocking
to produce some
very impressive
numbers.RAM DOES MORE than simply boost your PC’s processing power. If
you’re particularly software-savvy, you may be familiar with the
concept of a RAM disk: a block of RAM that is used by your system
as a temporary secondary storage drive. Using specific software
(such as DataRAM RAMDisk), it’s possible to partition a segment
of memory to be used as a drive. These virtual drives can be
incredibly fast—far faster than conventional SSDs or HDDs—and
theoretically have no limits on read/write times.
The main drawback of virtual RAM disks is that they lose all
stored data when powered down, making them particularly
vulnerable in the event of system crashes or power failure.
They’re also an expensive way of producing storage space to
work on files—RAM is simply more costly than physical drives.
However, there are other advantages. RAM disks can be ideal
for working with decrypted versions of encrypted files, and you
can set up regular backups of your data to a physical drive to
get around the risk of data loss on crashes. It’s possible to keep
data stored on a persistent storage drive, set to recreate it on
the RAM disk when the system boots. Most interestingly, RAM
drives can be used to access compressed files without having to
decompress them first, using systems such as cRAMfs on Linux.
With memory capacity ever increasing, RAM disks may become
more relevant in the not-too-distant future.
Other mechanics of RAM have been slowly integrated into
modern operating systems for ease of use. Virtual memory, for
example, involves the par titioning of hard dr i ve space as a “paging
file,” which is then used for storing excess data when the physical
RAM is operating at capacity. Windows does this automatically,
using the paging file as additional memory space to prevent
program crashes. This function can be disabled in Windows 10
to free up disk space, although it’s not recommended if you’re
running anything less than 32GB, and does put you at greater risk
of system instability. Modern BIOSes also incorporate “shadow
RAM,” where ROM functions instead use DRAM locations to
speed up access times. The benefits of doing this manually are
minimal, though, particularly with modern ROM chips.CPU
Differences
The Bottleneck
What Else Can My RAM Do?
maximumpc.com SEP 2019 MAXIMUMPC 29