The Definitive Review Of The 128MB OCZ Performance Enhanced SDRAM DIMM

Benchmark Results

Read Speed - CAS 3

FSB	Read Speed	Boost
158MHz	392.2 MB/s	+ 18.92%
150MHz	373.7 MB/s	+ 13.31%
133MHz	329.8 MB/s	Baseline

The read performance of the DIMM scales linearly with the increase in FSB speed. Overclocking it to the maximum speed of 158MHz afforded an increase in read performance of about 5% over that of 150MHz, which isn't too bad at all.

Read Speed - CAS 2

FSB	Read Speed	Boost
153MHz	420.8 MB/s	+ 15.22%
150MHz	413.5 MB/s	+ 13.23%
133MHz	365.2 MB/s	Baseline

At CAS 2, the maximum achievable clockspeed was only 153MHz, 5MHz less than at CAS 3. The extra 3MHz only improved the read performance by 1.77% over that of 150MHz. Hardly significant enough to matter.

Write Speed - CAS 3

FSB	Write Speed	Boost
158MHz	425.4 MB/s	+ 18.86%
150MHz	405.4 MB/s	+ 13.27%
133MHz	357.9 MB/s	Baseline

Just as it was with the read performance, the Performance Enhanced DIMM's write performance scaled linearly with the increase in clockspeed. Again, the extra 8MHz improved performance by 5% over that of the DIMM at 150MHz.

Write Speed - CAS 2

FSB	Write Speed	Boost
153MHz	421.9 MB/s	+ 15.30%
150MHz	414.4 MB/s	+ 13.25%
133MHz	365.9 MB/s	Baseline

Nothing much to comment here. Similar scale of improvement with each bump in the clockspeed. And again, the performance benefit (+1.8%) from the meagre extra 3MHz that the DIMM could take beyond 150MHz wasn't anything to talk about.

CAS 3 vs. CAS 2 Comparison

It's obvious that running this DIMM @ CAS 2 will significantly improve performance. But the charts above also show that most of the improvement only comes during reads. Write performance is also improved but not as much as read performance.

Overall, running this DIMM @ CAS 2 will improve read performance by 10.7%. In contrast, running at CAS 2 will only improve write performance by a paltry 2.2%! So, it makes sense to run this DIMM at CAS 2 if you can.