Intel Core i7-7740X X-Series Kaby Lake-X CPU Review

The CPU

The 7900X is on the left while the 7740X is on the right. The integrated heat spreaders are a bit different, but both use thermal paste between the dies and the integrated heat spreader. You might notice that the 7740X lacks the RFID chip in the upper right-hand corner of the PCB, as that is an enterprise feature held over from Xeons and the 7740X is not an enterprise part.

The bottom of the CPUs is also a bit different. The gold color of the pads differs, and there are some blue spots beneath sections of the 7900X that aren't present on the 7740X. The SMD components are also different at the center, and some are for power delivery. The 7740X doesn't use an integrated VR (IVR) like the 7900X; it gets its juice straight from the motherboard.

If you ever have to go from a 7900X to a 7740X, it would be prudent to clear your CMOS really well. The VRM pumps 1.8v into a 7900X, but the 7740X only should receive something below 1.3v, so clearing the CMOS would help ensure nothing bad happens.

Test Setup

• CPU: Intel Core i7-7740X
• Motherboard: One of the two below
• Cooler: Corsair H100i V2 AIO Water Cooler
• Memory: Corsair Dominator Platinum 32GB and G.Skill TridentZ RGB 32GB
• Video Card: NVIDIA GeForce GTX 1080 Ti - Buy from Amazon / Read our review
• Storage - Boot Drive: Samsung 950 Pro 256GB M.2
• Storage - USB Drive: Corsair Voyager GS 64GB - Buy from Amazon / Read our review
• Case: Corsair Obsidian 900D - Buy from Amazon / Read our review
• Power Supply: Corsair RM1000 - Buy from Amazon / Read our review
• OS: Microsoft Windows 10 - Buy from Amazon
• Monitor: ASUS PA328 ProArt 32" 4K - Buy from Amazon
• Keyboard: Corsair K70 LUX - Buy from Amazon
• Mouse: Corsair M65 PRO RGB - Buy from Amazon / Read our review
• Headset: Corsair VOID RGB Wireless - Buy from Amazon / Read our review

The ASUS PRIME X299 Deluxe was used for the benchmark portion of the review, along with Corsair's Dominator Platinum 3200MHz kit (at stock) as it's double sided.

For overclocking, we are using GIAGBYTE's X299 AORUS GAMING 9 motherboard along with G.Skill's 3600Mhz TridentZ RGB kit.

I also wanted to show ASRock's X299 motherboard. In our 7900X review, we showed you motherboards from all the vendors who had sent boards, and ASRock's motherboard was on its way, so we include it now. A review on this motherboard and the others will be out soon!