The Clarkdale Review: Intel's Core i5 661, i3 540 & i3 530

Final Words

When I first started testing Clarkdale I actually had to call Intel and ask them to explain why this wasn't a worthless product. The Core i5 661 is priced entirely too high for what it is, and it's not even the most expensive Clarkdale Intel is selling! The Core i5 670 is going to retail for nearly $300 and it won't even be able to outperform $200 quad-core competitors.

Intel admitted that these high end SKUs aren't going to be very high volume. Most users are expected to opt for the Core i5 750 instead of the i5 661 unless they absolutely need Intel's HD Graphics for some bizarre reason. The real volume is going to be in the Core i3 and that's where I believe Intel has a real winner here. Unlike the entry-level Lynnfield, you don't give up Hyper Threading with the Core i3 540 and 530. All you lose is Turbo. And since these are dual-core CPUs, Intel's Turbo Boost doesn't buy you all that much extra performance (+133MHz or +266MHz at most).

With the i3s you get a great dual-core chip that is competitive with AMD's Athlon II X4 line in many multi-threaded applications. AMD sacrificed its L3 cache in order to bring four cores down to reasonable price points. Intel's Core i3s start with two cores, a complete cache hierarchy, and give you Hyper Threading to improve performance in those multi-threaded scenarios. If you're doing a lot of video encoding or 3D rendering AMD's cheap quad-cores are going to be a better option, but for nearly everything else (gaming included) you'll be better off with the Core i3.

Even the integrated graphics performance isn't terrible, but we'll have to wait and see how the i3s perform with their lower clocked IGP.

These things also overclock ridiculously well. We got 3.8GHz out of the i5 661 at stock voltage and I'd expect similarly sweet results out of the i3s. Turbo isn't really important for two cores, it's only with quad-core that it really starts to matter - so just grab an i3 and overclock the heck out of it.

For a HTPC there's simply none better than these new Clarkies. The on-package GPU keeps power consumption nice and low, enabling some pretty cool mini-ITX designs that we'll see this year. Then there's the feature holy-grail: Dolby TrueHD and DTS HD-MA bitstreaming over HDMI. If you're serious about building an HTPC in 2010, you'll want one of Intel's new Core i3s or i5s.

A huge selling point for corporate markets is going to be Clarkdale's AES-NI support. The impact on disk performance with Bitlocker enabled is noticeable. Enabling Bitlocker caused my testbed SSD to take a 15% performance hit in disk I/O on Clarkdale vs. over 30% with Lynnfield. If you need to enable disk encryption as a corporate requirement, Clarkdale (and Arrandale) is going to help improve performance tremendously. Couple it with an SSD and you're in business.

To conclude I can only go back to my only real complaints about Clarkdale. The off-die, on-package memory controller hampers performance. We've taken a step back in terms of memory latency, a step we can't correct until Sandy Bridge. I can't help but think that Clarkdale would be so much more competitive if it had Lynnfield's memory controller. I guess we'll have to wait a year to find out.

The other issue is that its pricing at the high end just doesn't make any sense. There isn't a single Core i5 I'd recommend, but the i3s are spot-on. To Intel's credit, though, if it priced the Core i5s more aggressively, I'm not sure there would be much room for AMD to compete. Perhaps killing competition isn't what Intel wants either....