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Posted by
Toby Crundwell
on November 08, 2001
Manufacturers: Crucial
Technology / Crucial
UK & OCZ
Tech
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for Memory
prices here.
CAS
CAS = Column Access Strobe. A memory’s CAS rating is generally
comprised of 3 different settings; CAS Latency, RAS to CAS
delay and Precharge time. All of which are usually linked
and referred to simply as CL (CAS Latency). On the OCZ and
Crucial modules these settings were always the lower number
(although as we'll see they can be overclocked)
CAS Latency: This sets the CAS latency timing of the DRAM system memory
access cycle when SDRAM system memory is installed. Setting
this to 2 will yield better performance, although may be
less stable if your SDRAM is not CAS2 rated. 2.5 is slower
& should be used when DDR SDRAM isn't CAS2 rated or you
want to improve stability.
RAS to CAS delay: This sets the delay between the CAS & RAS strobe
signals. Basically setting this to a low number will improve
performance, setting this to a higher number can improve
stability (Particularly when running the memory above rated
speed).
Precharge delay: Much like the above 2 settings, setting this to a low
number will improve performance & setting this to a
higher number can improve stability (Particularly when
running the memory above rated speed).
Installation
As
was expected, there was nothing adverse about installing the
two DIMMs. Both ran faultlessly at a speed of 133Mhz.
Test
machine:
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AMD
Athlon Thunderbird 100Mhz FSB @ 850+Mhz
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Asus
A7A 266, FSB @ 100+Mhz
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Memory
running at clock + 33Mhz
-
OCZ
Titan 2 Ultra SE
SiSoft
Sandra 2001te standard’s memory benchmark was used to
compare the two modules.
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Crucial
PC2100
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OCZ
PC2400
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Default
speed
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133Mhz
DDR, CL2.5
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150Mhz
DDR, CL2.5
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ALU
memory bandwidth (default)
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352MB/sec
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385MB/s
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Optimum
speed
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151Mhz
CL2
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153Mhz
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ALU
memory bandwidth (optimum)
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389MB/s
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393MB/s
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We
see fairly predictable results, with the Crucial coming
within only 2Mhz of the OCZ, and with both willing to run on
decreased latencies. In fact, the Crucial could load up
windows at much higher frequencies, but Windows reported
registry errors at these breakneck speeds.
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