Hardware Reference
In-Depth Information
one thread per core, or vice versa? The answer to all of those questions is
both yes and no, because the winner will be different for different applica-
tions. Some applications are clock speed-bound, while others are core-bound,
thread-bound, or L3 cache-bound—or some combination of those factors.
The upshot is that on average you get $200 worth of performance, whichever
of these $200 processors you use.
But what about the Core i5-660 and -661 models? They appear to be identical
other than in power consumption. Why would anyone pick the -661 for the
same price as the -660, when the only difference appears to be that the -661
draws more power? Here's where we get into really minor differences:
• The -660 and -661 both include integrated Intel HD Graphics, but the -660
uses a basic graphics frequency of 733 MHz, while the -661 boosts that to
900 MHz for faster video performance.
• The -660 supports Intel Virtualization Technology for Directed I/O (VT-d),
a memory-mapping technique that has both advantages and disadvan-
tages. The -661 does not support VT-d.
• The -660 supports Intel Trusted Execution Technology, which is essentially
hardware support for Digital Restrictions Management (DRM). The -661
has no such support.
As it happens, we wanted to use a processor in this price range for our main-
stream system. So which one did we choose, and how did we choose it? All
four are excellent processors, but…
• We first eliminated the Core 2 Quad Q9300 from consideration. It's based
on older technology, but that's not necessarily a problem. We ruled out
the Core 2 Quad because it uses the obsolescent Socket LGA 775, which
would have limited our choice of motherboards and future upgrade/
repair options.
• We next eliminated the Core i5-750. It's an excellent processor, and for
some people would be the best choice of the four. However, it has the
highest power consumption of the remaining candidates, and lacks inte-
grated video.
• With the choice down to the Core i5-660 and -661, the decision becomes
almost a toss-up. In return for its somewhat higher power consumption,
the -661 provides faster integrated graphics. The -661 lacks VT-d (which
we'd kind of like to have just on general principles), but it also lacks hard-
ware DRM, which we'd definitely prefer not to have.
On that basis, we chose the Intel Core i5-661, but the truth is that any of the
other three would have done nearly as well.
Most people spend too much time dithering about which processor to install.
The only really important decision is how much to spend. After you make that
decision, it really comes down to the minor details. Here are the considerations
for each of the processor price ranges:
