Intel outed the addition of Hyper-Threading (HT) to its Kaby Lake Pentium series with little aplomb at CES; instead, the company mentioned the new capability in passing during our briefing.
The Pentium series traditionally consists of low-power, dual-core offerings with no HT. Pentiums serve as the low-end alternative to the i3 series, which features dual-core offerings with HT enabled. The addition of HT to the Pentium series expands its range, but there are still a few key differentiators compared to the i3 series.
The Pentium G4620 and G4600 have a 51W TDP, which is the same as their i3 "equivalents," whereas the G4560 has a 54W TDP, which is higher than all of the i3 SKUs (with the exception of the 60W unlocked i3-7350K). The Pentium G4600T and G4560T slot in as the low power Pentium offerings with a 35W TDP. The i3 "T" SKUs feature the same 35W TDP.
Intel's Pentium base clocks, which range from 2.9-3.7GHz, are also lower than their i3 counterparts. They also only feature 3MB of cache compared to the 4MB found in the i3 series (except i3-71xx models, which have 3MB of cache). The Pentium offerings provide the same HD Graphics 630 as the i3, though the two G4560 and G4560T SKUs step back to the HD Graphics 610.0
The Pentium series also forgoes support for the Advanced Vector Instructions 2 (AVX2) instruction set, which the i3 series supports. Some heavy enterprise workloads, such as databases, and more mundane video processing applications (among others), tend to use the AVX2 instruction set to boost performance, but it is unlikely that the omission will drastically affect a typical user.
Pricing is the key difference between the two, as the Kaby Lake chips command a ~$53-$63 premium. The lower price point makes the Pentium lineup very attractive for a number of low-power applications, including low-end gaming rigs, and the HD630/610 brings some multimedia-centric use-cases into view as well.
The HT-enabled Pentiums create a challenge to AMD's line of low-end processors, and of course, some will speculate that it appears that Intel is bolstering its low-end products in the face of AMD's pending Ryzen onslaught. In either case, the HT-powered Pentiums add a welcome new wrinkle to the low end. The processors are listed on Intel's ARK but are currently available only for preorder.
UPDATE: 1/12/17 - clarified i3 cache