Re: Memory use and performance issues




"david manvell" <davidmanvell@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:A3CB84A5-9882-4300-93F4-21093D033BB6@xxxxxxxxxxxxxxxx


"Mark H" wrote:

Initially, the amount of memory limits the WEI:
<256MB limited to 1.0
<500MB limited to 2.0
<512MB limited to 2.9
<704MB limited to 3.5
<960MB limited to 3.9
<1.5GB limited to 4.5
There are more, up to 5.9

Then comes bandwidth: MB/s
While you're CPU is fast, the memory may be bottlenecked when compared
to
your CPU output.
WEI compares what the CPU can produce on the data bus to what the memory
can
take in.

Lastly, latency:
Is your memory all working at the same speed? Or, are portions waiting
for
the other sticks to catch up?
This is crucial when you have more than one stick: all memory should be
identical in it's ratings (even so much as made by the same
manufacturer.)
If not, each stick will perform slightly differently and timings will be
out
of alignment. Three of the four sticks will be waiting for the fourth.
Do
you have the sticks in the right slots to support dual channel mode?

Go to: C:\Windows\Performance\WinSAT\DataStore
Open the most recent file with MS Word
Look for Memory Metrics.
I have a score here of 5.9
Memory Metrics: 9015
Memory: DDR2-800
Latency: 5 (Four matched 2GB sticks)

While I have 8GB memory, going further into the file I find a section
labeled Memory and it reports I only have 7GB. (See table above. I think
<6GB is the limit for 5.9) If you recall, x86 machines are limited to
about
3.2GB due to hardware addresses using the rest of 4GB. Either this
happens
on a x64 machine also, or I have something else going on here. (My video
card shares 2GB.) Point is, you may have less memory available than you
think. Is it all available?

Go a little further in the file and find: System Memory Bandwidth:
This is comparing CPU and memory bandwidth.
I get 9308 MB/s (average)
Each CPU is producing 4650 MB/s (average)
I have 2 CPUs
Since the total CPU output is equal to the Memory Input, my current
bottleneck is my CPU.
CPU rating: 5.6
(Note: I have a dual core 3.2Ghz. Same speed as yours, less
cores.)

Looking at these metrics will tell you where your bottleneck is on your
computer resulting in the low rating.
I would suspect:
Memory not matched.
Memory in wrong slots for dual channel.
CPU bandwidth > memory bandwidth


I reran the windows experience index after installing this latest video
card
and saw some improvement. I'm now at 5.0 with processors and 5.9 with
everything else. I'm surprised changing the video card affted it.
Unfortunately I am still seeing low framerates in World of Warcraft.

Here is my assesment file:

http://members.cox.net/dmanvell/2008-10-19Assessment.WinSAT.xml

I will look and see what the rating is on all my ram. Iirc I originally
had
2 one gig ram sticks and then I went and added 2 two gig ram sticks (For a
total of 6). I think all the memory in this computer is 400 speed. Can you
put faster memory in a computer? Or will it slow it down to the same speed
as
the others? Can these CPUs be changed out?


Pertinent details:
Your video card is now processing what your CPU was doing for graphics. This
relieves both CPU and main memory, but not your data bus.

VideoMemBandwidth = 41599 MB/s

Your memory is reporting only 4 GB available. Like me, your video card is
eating 2GB of shared memory. I thought this would lower your memory score,
but it did not.

Memory:
Bandwidth = 3640 MB/s (Mine was 9015 @ 800Mhz)
Total Physical
Size 6GB
Bytes 6372450304
AvailablePhysical
Size 4GB
Bytes 4610347008

CPU:
Bandwidth = 3505 MB/s (Mine was 9308 and gets a 5.6 rating)
Now this one is a little perplexing because WEI only tests each CPU, not
each core, and the information that leaves the CPU (actually hits the data
bus) is far less than what the individual cores are capable of. I hope that
makes sense. Based on this, I'm not sure I'd give this score a lot of
credence.

Disk Drive:
Bandwidth = 108 MB/s

Video:
SharedSystemMemory 2145648640

I would check your motherboard manual to see if you can support faster
memory, but likely not. If it can, keep in mind, all your memory will run at
the slowest rated stick. Your video card far outpowers your CPU, so check
nVidia and Blizzard sites for specific patches related to World of Warcraft.
(Your drivers appear up-to-date.) No matter how fast your video card is, the
data must eventually hit the data bus in some form and that will not be
faster than your FSB or disk drive. (So your CPU doesn't have to do all the
graphics calculations, but whatever is being calculated must be sent to the
video card and RAM.)

I think your ratings are stellar. As Ian pointed out, you are setup as a
server. To get the scores higher is going to cost you a motherboard, CPU and
memory change. Not sure it's worth it for a number. You will have to decide
if it's worth the additional frames/sec. But, if it's not stuttering, what's
the point.


.



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