Core i3 540 and 530
As stated in the intro, Core i3 is based on Clarkdale core and Westmere architecture, same as Intel Core i5 600 series and in fact the same applies even to the new Pentium G6950 processor. They are all physically identical processors based on the same Clarkdale core, and you might be asking yourself "what's the deal, why not buy the cheapest one?". The deal is in the list of features enabled, rather than implemented, in specific series. The most expensive and fastest Core i5 600 series support a complete list of features and technologies implemented in the Clarkdale core. Performance wise the most important ones are by far Hyper Threading and Turbo Boost, and that's exactly where differentiation in the series happens. Unlike Core i5 600, the cheaper and slower Core i3 500 series come without Turbo Boost feature and lower clocks for the CPU core. The new Pentium processor on the other hand comes without Hyper Threading and Turbo Boost making it a simple dual core with fixed maximum clock. Our chart below presents all the differences between models and series of Clarkdale processors.
|Processor||Core i5 670||Core i5 661||Core i5 660||Core i5 650||Core i3 540||Core i3 530||Pentium G6950|
|Core speed||3460 MHz||3330 MHz||3330 MHz||3200 MHz||3060 MHz||2930 MHz||2800 MHz|
|Un-Core speed||2400 MHz||2400 MHz||2400 MHz||2400 MHz||2130 MHz||2130 MHz||2000 MHz|
|GPU speed||733 MHz||900 MHz||733 MHz||733 MHz||733 MHz||733 MHz||533 MHz|
|L3 cache||4 MB||4 MB||4 MB||4 MB||4 MB||4 MB||3 MB||Hyper Threading||Yes||Yes||Yes||Yes||Yes||Yes||No|
|Turbo Boost||3760 MHz||3600 MHz||3600 MHz||3460 MHz||Disabled||Disabled||Disabled||TDP||73 W||87 W||73 W||73 W||73 W||73 W||73 W|
As you can see, Core i3 lost only Turbo Boost which doesn't make that big of a difference, but keeps the most important Hyper Threading feature, enabling it to process four threads on two CPU cores at the same time. Also supported are AES instructions for data encryption, and the QPI link speed which is used for CPU-IGP communication is lowered from 2.40 GHz to 2.13 GHz. On paper this should lower some memory bandwidth, but in real world it has no effect on processor performance whatsoever. Core i3 500 also has the same amount of L2 (256 KB per core) and L3 (4 MB shared) cache memory, the GPU core in the IGP part of Clarkdale is clocked at 733 MHz and most processors carry the same TDP at 73 W (Core i5 661 excluded).
Now that we covered the major differences between the two series it's time to introduce the only two representatives of Core i3 series to date, the Core i3 540 and a bit lower clocked Core i3 530 models. As you can see from CPU-Z screenshots, Core i3 540 is clocked to fairly high 3.06 GHz and 530 is clocked just 130 MHz slower making it 2.93 GHz. Except for clocks these two are identical in every other way. The both have same list of supported features, specifications and TDP.
The CPU die on both parts is made in Intel's latest 32 nm process node and combined with an updated 45 nm IGP that packs integrated memory controller, PCI-E bus controller and Intel's graphic core. Together they make Clarkdale with a total core die size that measures 195 mm², of which 81 mm² makes up the dual core CPU part and 114 mm² IGP part.
End frequencies of both models are products of 133 MHz BCLK and processors frequency multiplier. Faster 540 model has a multi of 23 and slower 530 model comes with multi of 22. These values are locked upwards, and can only be lowered if the motherboard BIOS enables it. So no matter if you're running single threaded or multi threaded applications, core frequency will always be at 3.06 GHz and 2.06 GHz respectively. There's no need to cry over lack of Turbo Boost as it adds negligible performance increase in most cases, and you get a significant price drop over i5 600 to compensate. If you're an overclocker let me just confirm your thoughts - they are spot on. These processors are very overclocking friendly and don't cost a small fortune like i5 600 processors.
Core i3 540 is currently priced at $140 and i3 530 at $125 making them replacement parts for mostly unsuccessful Core 2 Duo E7000 series, and probably E8000 models as well. It doesn't stop there because Hyper Threading makes these processors a serious threat for Core 2 Quad Q8000 series at significantly lower price. AMD's Phenom II X2 might get a retirement signal from here on, and the future is not looking bright for some triple core models as well. Fortunately for AMD it has a very strong quad core lineup in this price segment, and the real question is can the new i3 500s match up against them.