--- product_id: 277466629 title: "Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory" brand: "crucial" price: "FREE" currency: JPY in_stock: false reviews_count: 4 url: https://www.desertcart.jp/products/277466629-crucial-ram-ct4g4dfs6266-4gb-ddr4-2666-mhz-cl19-desktop-memory store_origin: JP region: Japan --- # 2666 MHz blazing speed 1.2V low power efficiency 288-pin UDIMM form factor Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory **Brand:** crucial **Price:** FREE **Availability:** ❌ Out of Stock ## Summary > ⚡ Upgrade your desktop speed—because slow is so last decade! ## Quick Answers - **What is this?** Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory by crucial - **How much does it cost?** FREE with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/277466629-crucial-ram-ct4g4dfs6266-4gb-ddr4-2666-mhz-cl19-desktop-memory) ## Best For - crucial enthusiasts ## Why This Product - Trusted crucial brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Energy Smart:** Runs efficiently at just 1.2 volts, keeping your system cool and power bills low. - • **Boost Your Workflow:** Experience seamless multitasking and faster app launches with 4GB DDR4 memory at 2666 MHz. - • **Perfect Compatibility:** Use Crucial’s System Scanner or Advisor Tool to ensure flawless fit with your desktop. - • **Plug & Play Simplicity:** Effortless installation with no tech skills needed—get up and running in minutes. - • **Trusted Micron Quality:** Backed by 42 years of memory expertise and rigorous testing for rock-solid reliability. ## Overview The Crucial CT4G4DFS6266 is a 4GB DDR4 desktop memory module running at 2666 MHz with a 288-pin UDIMM form factor. It operates at a low voltage of 1.2V for energy efficiency and is backed by Micron’s 42 years of expertise, ensuring reliable performance and easy installation for enhanced system responsiveness and multitasking. ## Description Full description not available ## Features - Improve your system's responsiveness, run apps faster and multitask with ease - Install with ease; no computer skills required. How-to guides available at Crucial - Compatibility assurance when using the Crucial System Scanner or Crucial Advisor Tool - Micron quality and reliability is backed by superior component and module level testing and 42 years of memory expertise - ECC Type = Non-ECC, Form Factor = UDIMM, Pin Count = 288-pin, PC Speed = PC4-21300, Voltage = 1.2V, Rank and Configuration = 1Rx16 ## Technical Specifications | Specification | Value | |---------------|-------| | Brand | Crucial | | Product Dimensions | 13.33 x 0.08 x 3.12 cm; 16 g | | Batteries | 1 Lithium Ion batteries required. | | Item model number | CT4G4DFS6266 | | Manufacturer | Crucial | | Series | Crucial 2666 MT/s DIMMS | | Colour | Green | | Form Factor | DIMM | | Processor Count | 1 | | RAM Size | 4 GB | | Memory Technology | DDR4 | | Computer Memory Type | DDR4 SDRAM | | Memory Clock Speed | 2666 MHz | | Voltage | 1.2 Volts | | Wattage | 3600 | | Are Batteries Included | No | | Lithium Battery Energy Content | 2 Kilowatt Hours | | Lithium Battery Packaging | Batteries packed with equipment | | Lithium Battery Weight | 2 Grams | | Number Of Lithium Ion Cells | 5 | | Number of Lithium Metal Cells | 5 | | Item Weight | 16 g | | Guaranteed software updates until | unknown | ## Product Details - **Brand:** Crucial - **Computer memory size:** 4 GB - **RAM memory technology:** DDR4 - **Memory speed:** 2666 MHz - **Compatible devices:** cellphone ## Images ![Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory - Image 1](https://m.media-amazon.com/images/I/61j3CTxnXVL.jpg) ![Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory - Image 2](https://m.media-amazon.com/images/I/51o+mxsOM+L.jpg) ![Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory - Image 3](https://m.media-amazon.com/images/I/61WrSm1ISgL.jpg) ![Crucial RAM CT4G4DFS6266 4GB DDR4 2666 MHz CL19 Desktop Memory - Image 4](https://m.media-amazon.com/images/I/61DPFAmugxL.jpg) ## Available Options This product comes in different **Size, Style** options. ## Questions & Answers **Q: I bought a single 8Gb stick of this for my build - it says 2400 but is running at 1200. Why? Is it only 2400 if I run 2 sticks?** A: Modern DRAM modules support double data rate (DDR) transfers, meaning that although they function at a given clock speed, they transfer data during both the rise and fall of a CPU clock cycle, allowing for double the data transfers their native speed, or frequency, would suggest. Some diagnostic or system information software does not express this clearly, only reflecting the modules' frequency in megahertz (MHz), making such feedback suggest that your parts are only running at half their possible speed. For example, DDR3-1600 supports 1600 megatransfers per second (MT/s) due to its nature as DDR memory, but runs at 800 MHz. **Q: What is the difference between crucial ct8g4dfd824a and crucial ct8g4dfs824a?** A: Thanks for your question. CT8G4DFD824A is a dual ranked part and CT8G4DFS824A is a single ranked part. More information on this can be found here: http://forums.crucial.com/t5/Crucial-memory-for-PC-systems/What-is-a-memory-Rank/ta-p/126346 **Q: If I add a 8gb for my Dell i5675 will it be compatible with the 8gb thats already in my pc?** A: Thank you for contacting Crucial and for your question. The part number that you provided is 100% compatible with your system. That being said, we can guarantee that our memory will work with your computer, but we have no way to guarantee that it will work with what is currently installed in the system. I can tell you that most consumer systems out there can mix different brands of memory without running into any issues. **Q: Crucial 8gb single ddr4 2400 mt/s (pc4-19200) dr x8 unbuffered dimm 288-pin memory - ct8g4dfd824a can it compatible with msi gaming h110?** A: Yes, CT8G4DFD824A is compatible with the MSI H110M GAMING. ## Customer Reviews ### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars Basic RAM, easy to install, great value *by A***L on Reviewed in the United Kingdom on 3 July 2020* The packaging:I ordered the 32GB kit which consisted of 2x16GB DDR4-2666 UDIMM sticks. They come in plastic packaging to keep them safe for transport. The packaging is able to be opened by hand which is a huge positive for me as quite often things like this come in plastic packaging which has no discernible opening and which must be opened by either knife or scissors through a layer of plastic then prised apart. Not so with this. Just insert your finger into the packaging and then open away. Excellent. The only improvement they could make to this would be for some more environmentally sound packaging.The memory itself:Please, please, please, check what RAM your motherboard and CPU supports before ordering it. If you do that, then I have no doubt that it will just work straight out of the box. Crucial does a great job of providing a compatibility checker on it's own website which I would highly recommend checking out before ordering any RAM.The installation:This couldn't be more simpler. Locate the correct RAM slots on your motherboard (this is going to vary by motherboard supplier), pull on the tabs to open up the slots and then click in the RAM sticks into each slot. If you are installing 2 RAM sticks into 2 slots, this is fairly straight forward. If you have 4 slots like I did, then make sure you're populating the correct two slots - again, check the manual of your motherboard for details here. If you already had a RAM stick in any of the slots that you're using, take it out before installing any RAM. There is a correct orientation of the RAM stick, if you look at the bottom of the stick, you'll notice there is a notch in it, which is slightly off centre. Use this notch to line up the RAM stick into the RAM slot and press it in. It can feel quite firm, so don't be scared, it should just be able to press in with a click by firmly pressing down on both sides of the RAM stick.Conclusion:If you want/need more RAM, this is a great, low cost option for adding some extra memory into your system. You'll notice a lot of improvement if you're coming from a lot less RAM (I went from 8GB to 32GB). The sorts of improvements you can expect are better performance of multi tasking which is absolutely essential for someone like me who has many processes running at the same time. Also, if you're a Chrome Tab lover, you can't get enough RAM. ### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars Works a treat. *by W***Z on Reviewed in the United Kingdom on 2 December 2023* Should stop "out of memory" errors. ### ⭐⭐⭐⭐⭐ 5.0 out of 5 stars Great value 32GB module *by J***C on Reviewed in the United Kingdom on 23 June 2021* NOTE: To avoid any confusion - I bought 2x Qty of these 32GB DIMM modules, which are sold individually! - So pictures show multiple but you will only actually get one of these. (I was being tight - because it was about £8 cheaper to buy 2x individual at the time than a kit with 2 modules!)I decided to bite the bullet and get myself a memory upgrade. Seeing as recommendation in motherboard manual was to either have 1 DIMM, 2 DIMMs or 4 DIMMs. I decided to buy 2x of these 32GB modules.I'd only recently upgraded my existing 2x 8GB to 32GB by adding another 2x 8GB. So the natural thing was to take out the newly added 2x 8GB (which was 3200mhz RAM and use them elsewhere in another machine which could take advantage of it).Before ordering do note that this memory is UDIMM (unbuffered) memory, which should work for most desktop motherboards, and I'd say is pretty much the standard. Having checked, all my existing RAM is unbuffered (including some Crucial Ballistix 3200MHZ) - but worth checking out nevertheless before you order. I did manage to verify compatibility on the website for my motherboard.So these items arrived with minimal packaging, just a plastic protective case, which is fine and I do like this approach. Do note that this RAM doesn't come with heat spreaders. In my opinion they're unecessary, but it does mean you have to handle the modules with a bit care sinceSwitching off the PC, and removing the old modules was fairly easy. Using the removed modules as a guide to work out which way around the new ones went in (though you'd work it out pretty quickly without). Simply then carefully push the new modules in, ensuring they go all the way along into the slot - be careful if you apply a lot of force and it's not into the slot straight, you could damage the DIMM module or the motherboard.Once in, I switched on and went into the BIOS to check the memory was detected - it was. The new modules are 2666Mhz, but my existing 2 RAM modules are 2400Mhz RAM, so the overall running I believe is then restricted to the lowest of the RAM speeds. For me this is fine and as people say, in everyday usage you're usually better off with more slower speed RAM, than less amount of higher speed RAM.Running in WIndows, Task Manager shows up all the RAM, and I can now happily run multiple VMs etc without excessive paging to disk.It's only been one morning but complete stability as far as I can tell. Please assume that this is the case ever since this review - if are any problems with these modules at any point in future, I will be updating this review to reflect that.I bought 2x of these modules at £128 each at time of review and I felt it's good value at the price. Definitely very happy so far.Hope you found this useful. ## Frequently Bought Together - Crucial RAM 4GB DDR4 2666 MHz CL19 Desktop Memory CT4G4DFS6266 - Crucial 32GB Kit (16GB x 2) DDR4 3200 MHz (PC4-25600) UDIMM 288-Pin Memory - CT2K16G4DFRA32A - Crucial 16GB (2x8GB) DDR4 RAM Kit 3200 MHz (PC4-25600), Downclockable to 2933/2666 MHz Laptop Memory SODIMM 260-Pin, Compatible with Intel & AMD Laptops – CT2K8G4SFRA32A --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/277466629-crucial-ram-ct4g4dfs6266-4gb-ddr4-2666-mhz-cl19-desktop-memory](https://www.desertcart.jp/products/277466629-crucial-ram-ct4g4dfs6266-4gb-ddr4-2666-mhz-cl19-desktop-memory) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-10-01*