April 26, 2010
The Intel Core i5 750 probably is a better choice for the future, but it really depends on what you want to do with your system and what software you run. A true quad core like the 750 will almost always beat out a dual core – even a dual core with hyperthreading like the 650/660/661 in synthetic benchmarks. Those don’t tell the whole story of course. If the software you run most is primarily single threaded, the Intel Core i5 650 might give you overall better throughput with your work tasks since it’s turbo boost goes higher than the 750’s. Most older games were single-threaded, but many of the new games are not. If you’re not using this for games then that’s not a consideration.
One thing the 650/660/661 did was to push the memory controller off to the 45nm chip inside the package (along with adding integrated graphics there). The memory throughput of the 6xx line is a bit disappointing, and I think that’s where the 650 probably gets clobbered compared to a 750. Anantech’s review (page 2) shows the numbers: http://www.anandtech.com/show/2901/2 If you did a lot of video encoding/editing/transcoding for example, those apps are generally heavily thread aware and also move a lot of data around on disk and in memory. The 750 is significantly better in that regard. In benchmarks for gaming, the 750 still generally beats the 650 even with the 650’s higher turbo boost because of this and the fact more recent games use multi-threading.
The 650 does have the AES New Instructions that help with encryption/decryption. If you use Bitlocker on your hard drives, this will help a lot. If you don’t use Bitlocker then it’s not much of an issue. The 650 has integrated graphics, which are unfortunately, integrated graphics performance-wise. This IGP seems to be Intel’s best to date, which really just means it sucks less.
The 650 is also based on the 32nm die size which means less power is required. It also has fewer transistors (since it only has two hyperthreaded cores) to start with – nearly half in fact. It would probably be incredibly power efficient if not for the integrated graphics in a sister (45nm) chip in the same package. The 73W TDP (650) versus 95W TDP (750) isn’t going to make a lot of difference in the size of power supply needed. In fact in terms of idle power consumption Anandtech found the 750 to be more efficient. http://www.anandtech.com/show/2901/15 That’s not true under load however.
Both the Guru of 3D and Anandtech reviews reached the same conclusion. The Intel Core i5 650/660/661 make little sense against faster and often cheaper existing Intel CPUs. The lower end 630 makes more sense in home theater PCs with the IGP able to handle HD playback.
