Darklight said:
I am using a amd fx-8120 with
crucial ballistix sport 1600mhz 2x4gig cas 9-9-9-27
which is the best ram out of these
crucail ballistix tracer 1866mhz 2x4gig cas 9-9-9-24 £74.99
corsair vengance 1866mhz 2x4gig cas 10-10-10-27 £65.99
kingston hyper beast 4x4gig 1866mhz case 9-11-9-24 £71.99
paitriot viper black mamba 2x4gig case 9-9-9-24 £65.99
and will i see a perfomance increase in gamming
Or do you have another recommendation in the above price range
When the game is loaded and you alt-tab out, what percentage
of the existing RAM is in usage ?
Maybe the Microsoft Flight Sim uses a lot of RAM, but I doubt
the others go all the way to 8GB. The Microsoft Flight Sim
pre-fetches map data, and it's possible it might make usage of
the RAM. I don't know if other games go that crazy with the
RAM usage.
The best RAM performance, comes from the combination of clock speed
and low CAS. That's about the best you can do. And the lightest
bus loading (which happens with two sticks rather than four sticks).
I check the reputation of the RAM products, on Newegg or Amazon.
If there are DOAs, early failures and the like, that's not a good
recommendation. With some RAM products, you can tell from the reviews
that they're not "making their timing". In other cases, there
are no reports of trouble using the stock settings listed on
the package.
If your current RAM runs 1600, combining a faster product, it'll still
run at 1600. As otherwise, the old RAM would be run over-speed. Nothing
wrong with trying to run it faster than spec, just no guarantees on
error rate.
If they're all 1866MHz CAS9 or CAS10, then the CAS9 is faster.
If mixing RAM products, you want to match voltage expectations.
If one set ran 1.5V and you mixed a 1.7V RAM product with it,
it would be harder to make both of them happy. You would then
need to research, whether there are any issues running the 1.5V
product, at 1.7V or not.
I expect command rate is probably already set at 2, even with
a single pair of sticks. So it probably won't matter that
command rate 2 would be needed to run four sticks. That halves
the rate that the command bus can be used, and has a slight effect
on performance. (The command bus isn't normally full, so it doesn't
cut transfer rate in half or anything. But it still does have
an effect on overall rate.)
The third set in your list is a set of four, so will mean removing
the current pair of sticks.
You would also want to research the speed options of your processor.
To see whether it is possible to set it to 1866MHz. On AMD,
usually you can run one clock rate level faster with two sticks,
than with four sticks present. And I haven't been keeping track
of AMD lately. I don't even know if I could find a spec to tell
me, what the clock rate options for 2 or 4 sticks would be. It's
not something that's well documented. (If you do find the spec,
the spec covers a lot of different CPUs, and makes it tough to
figure out.)
*******
From an advert for FX-8120
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103961
"The AMD FX Processor features a high-bandwidth, low-latency
integrated memory controller that supports up to DDR3-1866
and new low voltage memories of 1.35V and 1.2V"
So that tells you, it can run at least two sticks at 1866. But
not what speed is supported with four sticks. It could be the
next step down. And pulling a QVL from Asus, isn't making it
clear either. I can find entries in a QVL, even at lower
clock rates, where they had a failure to support four sticks.
(Meaning, they used stock settings and got errors. A real user,
would have to tune the settings a bit, until the set of four
sticks was happy. Maybe the settings shown on the RAM package,
could not be met - and it would be the fault of the processor.
So maybe a set of four at 1866, runs 1866, or you end up running
them at 1600.)
From one of the reviews on Newegg for the FX-8120.
"Cons: Had to under clock ram to 1600mhz with 16gb do to
cpu memory controller problems with more than 8gb
installed. 8 gigs will run with no problem @ 1866mhz."
I mention that, just to set your level of expectation. While you
might coax 1866 out of four sticks, there are no guarantees.
Paul