Intel 32 nm Core i5 661 CPU

The recently launched Intel Core i5 661, codenamed
Clarkdale, is a Westmere architecture based dual core CPU based on the latest
32nm fabrication technology. This desktop processor is meant to be highly power
efficient and produce lesser heat. Though it is supposed to work at 3.33GHz but
with overclocking, it can attain a max of 3.60 Ghz with a single active core.
When both cores are active, overclocking ups the clock speed of the processor to
3.46 GHz. The interesting point to note here is that the processor goes into
overclocking mode automatically as per the requirement of the applications
running on it. Intel Core i5 661 has level 3 cache of 4 MB. Also, the processor
caries on-chip GPU. This facilitates better graphics output thereby enabling the
user to play a certain degree of high end games without plugging in an
additional graphics card. The processor connects through a LGA1156 socket which
was used to connect the previous Lynnfield processors (Core i7 and Core i5). We
tested and compared the new processor with  Intel Core i5 750 (quad core),
codenamed Lynnfield, which we tested about a month back.

Performance

In 3DMark 06, the Intel Core i5 661 managed a healthy 3876 score whereas the
Intel Core i5 750 notched up 4589 (reviewed in Dec 09 issue). Although the
processor scored lower, it is still good, considering that Core i5 661 is a dual
core processor while the Core i5 750 is a quad-core processor.

When put to the POV-Ray test, the result for 661 was a
render average of 43,240 PPS in 2.52 sec over 1,96,608 pixels whereas Core i5
750 achieved 78,643 PPS in 2.50 sec over the same number of pixels. As expected,
we observed an improvement in the benchmark results when the same setup was
tested using Windows 7 Ultimate.

In the power test, the entire test bed including the
monitor consumed 65 watts in idle mode, hardly any power in stand-by and 145
watts running at full blast (overclocked). Compare this with the Intel Core i5
750 architecture where the entire test bed consumed 99 watts when idle, 85 watts
on stand-by and 170 watts running at full load. This is a major plus for the
Intel Core i5 661 as it regulates the system power consumption much better than
the Core i5 750. This translates to a good amount of saving in terms of
electricity and backup.

Since the Intel Core i5 661 is another dual core processor,
we tried to compare its power consumption with the previous generation of dual
core processors from Intel as well, by keeping a similar test bed. Our tests did
justify Intel's claims to a certain extent. Yes, the Intel Core i5 661 is power
efficient as compared to the previous dual core processors also, as can be seen
in the table-Power consumption comparison with the previous generation Intel
dual core processors.

Although these results are great for the processor but it
should be noted that the Intel Core i5 661 processor delivers this level of
power efficiency with the Intel DH55TC motherboard only. We tested the power
efficiency of the processor as a standalone entity by keeping the same test bed
and changing the motherboard, and exciting results were observed. We found that
the processor was not as power efficient on the other motherboards namely the
Gigabyte P55A-UD6 and Asus Maximus III Gene. Please refer to the table-Power
consumption of the processor across motherboards.

Bottomline: The
processor provides equal if not better performance as compared to quad core
processors, the Core i5 750, but slightly overpriced considering it's a
mainstream dual core processor.