G.SKILL RipjawsV Series DDR4 RAM 64GB (2x32GB) 2666MT/s CL18-18-18-43 1.20V Intel AMD Desktop Computer Memory U-DIMM - Black (F4-2666C18D-64GVK)

Easy to install, built my first pc and had no problems with them.

I tend to like gskill. Have not had a bad stick yet. In the computers i have built, they are all still going. unlike other brands i have used. also the dark pro fan fan will fit over this memory. I have it installed in my own case.

I wasn't sure if I would see a difference going from 32 GB of RAM to 64 GB. All I can say is wow. There is a noticeable difference when I load a program. The average wait time while call of duty loads has been cut down. Two thumbs up.

Install, easy etc, but works! My 13 month old ram from my IBUYPOWER failed, UGH! These seem good, hard to rate, I am not too techy but i went from 16gb to 64GB.WA WA WE WA NIIICE!

Put in my i9 system to boost it to 128GB

don't know anything about memory timing-all I know is it works

Memory worked perfectly out of the box.

This review is for "G.Skill RipJaws V Series 64GB (2 x 32GB) 288-Pin SDRAM (PC4-21300) DDR4 2666 CL18-18-18-38 1.20V Dual Channel Desktop Memory Model F4-2666C18D-64GVK"My machine specs are Ryzen 7 1700x, Asus Prime X470-Pro (Rev X.0x), Sapphire Radeon RX580 (8GB); These DIMMs occupy two slots. Windows 7 64-bitMotherboard BIOS is version 5821 date 01/05/2021. AMD Ryzen SOC rev. 00. AMD Southbridge X470 rev. 51I do NOT overclock, although the ASUS BIOS +Ryzen does by default, so my Ryzen 7 1700x runs at 3492.4 instead of the nominal 3400, with split-second boosts to 3894.3 MHz. (I'd argue that if "overclocking" is within CPU specs, it's not actually overclocking, especially when you pay more for it. However with AMD, the price/performance ratio curve stays fairly consistent.)----------BEGIN NERD STUFF---------- CPU-Z Memory tab says: DDR4, Dual Channel, 64 GBytes, Uncore/DRAM Frequency: ~1330.2 MHz (constantly varying by a MHz or so) FSB:DRAM - 3:40, 18:18:18:43:61:1T CPU-Z SPD tab says: Dual Rank, 32GB Module, DDR4-2667 (1333 MHz), 1.20 Volt Part Number: F4-2666C18-32GVK Module Manuf.: G.Skill DRAM Manuf.: SK Hynix There's four JEDEC Timings. My BIOS autoconfigs correctly to the last one (1333 MHz or DDR4-2667).The little CPU-Z benchmark gives me ~403 and ~4200, although when Windows first loads I can get ~430 on the Single Thread, butAfter a few minutes, it drops to the ~403. I've shut down every service and program until the system is barely usable and it's still at ~403, so it's a mystery.----------END NERD STUFF ----------Long time ago, I used Kingston memory and that was always 100% reliable. When they didn't have what I wanted, I tried to use early OCZ products, which were uniformly garbage. Covering an OEM manufacturer's label with a dot-matrix printed label on a DRAM module doesn't give you more MHz. Who knew?) Whereupon I found G.Skill, whose products have been uniformly excellent. I contacted them once and got a personal response with concise, correct information, so there's that too. I mean, everyone claims great support and warranty now, but time, frustration, and mental energy have a monetary value too.I have no current or previous association or continuing contact with anyone mentioned here, and wasn't given, offered and did not seek, swag by anyone at any time for any reason in the context of this review.Anyway, installed these AS PER MANUAL (seriously, guys, you can't just jam them anywhere they fit) and got a stable system. For me, "stable" is a binary concept. A computer is either stable or it isn't. There's no "it's stable unless.." or "It's mostly stable" or "it's 99% stable".This is 100%, never crashed once stable. There is one hitch with the BIOS, you may have to turn the power off (with Windows or the case button, not the power supply) and start from OFF rather than rebooting, or it will hang while loading the Win7 pulsing logo thing. Once Windows loads, it's literally perfect. I use Win7 and an old BIOS so YMMV.tl;dr: For a Ryzen system only, turn your power supply off at the toggle switch then hit the ON button on the case, to eliminate any "stored" power. Install the two DIMMS into slots AS ADVISED IN YOUR MANUAL (usually NOT two adjacent sockets). Turn things back on and optionally run Windows Memory Test. Perfect!

Work well on Gigabyte B450 AORUS M (rev. 1.x) with Athlon 3000G. Had a pair of Teamgroup previously which is horrible.