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Top Customer Reviews
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A possibly useful explanation for 27" iMac buyers
By
Maynard Handley
on
January 29, 2013
Verified Purchase
Some buyers have expressed concern after buying this RAM and installing it in their iMacs (27" Ivy Bridge model, late 2012).
That iMac is specced for DDR3 1600 RAM, and ships with RAM like that, but after you install this Corsair RAM your iMac will show that it is running aRAM at 1333 MHz, not 1600. So:
(a) The reason this is happening is that DRAM is (to simplify things tremendously) described by two parameters. One is bandwidth (essentially how much data it can transfer per second), the other is latency (how long does it take to set things up before that data starts being transferred).
(b) Your APPLE RAM in the iMac has a bandwidth of 1600MHz and a latency (CAS) of 11 cycles.
The Corsair RAM has a bandwidth of 1600MHz and a latency (CAS) of 10 cycles.
(c) Given that the two sets of RAM do not have identical specs, how should the memory controller configure things for optimal performance? The timings have to be identical for both sets of RAM, meaning they have to run with identical bandwidth and identical CAS.
(d) The CORRECT solution in this case would be to run both at 1600MHz and CAS of 11. However the solution chosen by the memory controller (I am guessing this is handled automatically by Ivy Bridge, not by Apple firmware, but I honestly have no idea) is to retain a CAS of 10, and drop the bandwidth to 1333, which is slow enough that the Apple RAM can run at a CAS of 10 rather than 11.
This is not a completely crazy solution. For most purposes, latency is more relevant to performance than bandwidth, so if you are faced with having to choose one over the other, you should choose to drop bandwidth while preserving latency. It's just unfortunate than in this case the algorithm (which, remember, has to work for the possibility of people plugging in four RAM DIMMs, possibly all from different manufacturers, with different bandwidths and latencies) chooses a solution that is slightly sub-optimal compared to the best possible solution.
(e) Does it actually matter? Short answer: no. Neither Apple nor Corsair have lied to you about their RAM, and as a practical matter the difference in performance between CAS 10 and CAS 11 ram, or between running at 1600 vs 1333 is negligible (like 1%). Yes, you can undoubtedly craft some benchmark which is sensitive to the issue and which magnifies the problem, but for any real app it just doesn't matter.
If you are so obsessive that you cannot stand this, if you buy a second batch of Corsair 16GB RAM and replace the Apple RAM, you will get back to 1600MHz, now at CAS 10 rather than CAS 11. But you honestly won't notice any performance difference.
Bottom lines:
- The extra RAM is nice --- it means paging on my iMac moves from being a rare occurrence to a non-existent occurrence, and allows that much more file system data to be stored in RAM;
- iMac will show the speed of your combined system (if you bought only two sticks, not four) as 1333 MHz, not 1600;
- There is no reason to be upset or worried about this. It does not mean anyone cheated you or that your system is running slower than it otherwise would.
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Works perfectly on a Late 2011 MacBook Pro & it Works on 2012 Models too
By
ReneB
on
January 8, 2014
Size: 16GB KIT (8GBx2)
Verified Purchase
I'm pleased to report that indeed, 16 GB of RAM does work correctly in the 2011 MacBook Pro, and, it is even recognized at it's full speed: 1600 MHz. All the functions of the MacBook Pro work correctly, including waking from sleep. Having this much RAM may seem like too much, but it is great if one uses several programs at a time or works with large datasets or image files.
Installing this RAM is relatively easy. There are instructions in the MacBook Pro's User Manual and online at Apple Support; even nicer instructions with step-by-step pictures can be found at sites like ifixit. Basically all one has to do is remove the screws on the bottom of the case, being careful to keep track of location of three of the screws that are longer than the rest.
As for quality of the Crucial RAM, the actual memory chips are by Micron, a respected manufacturer that supplies Crucial with most of the RAM they sell. After installing the RAM, I used the Apple Hardware Test (AHT) to verify that this RAM worked as it should in my MacBook Pro. I followed up on the AHT by running Memtest overnight to test the RAM - it passed with flying colors!
You may wonder how come it's ok to use 16 GB of RAM when Apple specified a maximum of 8 GB of DDR3 1333 MHz RAM for the 2011 series of MacBook Pro laptops? As you can see if you peruse the web, there are many, many reports of users installing and successfully using a maximum of 16 GB of RAM in the 2011 MacBook Pro laptops. The reason why Apple specified only 8GB as a maximum is that when these MacBook Pros were released, RAM modules denser than 4GB were not available in the appropriate sized SO-DIMM. With the subsequent improvement in RAM manufacturing technology, it's now possible to use up to 16 GB of RAM in the 2011 MacBook Pros. It's simply the case that Apple has not upgraded the specifications of the 2011 MacBook Pro.
In sum, if you are considering increasing the RAM in your MacBook Pro, and it's a 2011 model, it's safe to use this DDR3 1600 MHz RAM instead of the 1333 MHz RAM. You may ask why would one want to use 1600MHz vs. 1333 MHz. I choose to do so because, surprisingly, the 1600 MHz version was actually cheaper than the slower 1333 MHz type. It may not always be the case because RAM prices are very volatile, but it bears checking into if you are shopping for new RAM.
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Great upgrade for Lenovo Y410P, HP Chromebox. CT2K8G3S160BM/CT2C8G3S160BM and CT2KIT102464BF160B/CT2CP102464BF160B are identical
By
ƒůℤźϔ ωൠ≥ζŷ ♥☮♭♩♪♫♬♮☯☺♡✈
on
January 31, 2014
Size: 16GB kit (8GBx2)
Verified Purchase
I purchased the Crucial CT2K8G3S160BM 2x8GB to increase the memory in my Lenovo Y410P laptop from 8-GB to 16-GB. My Y410P has two memory slots, and one slot was already occupied by a factory-installed Samsung M471B1G73QH0-YK0 8-GB memory card. I probably could have just added another 8-GB card. But to avoid any possible memory glitches, I prefer not to mix-and-match memory cards of different types. The existing Samsung memory was PC3L/DDR3L, with the 'L' signifying that it is low-voltage 1.35V memory, whereas the standard PC3/DDR3 memory uses a higher voltage of 1.50V. You should not combine memory of different voltages or use memory with incorrect voltage since your laptop may not even boot up. To further maximize compatibility with my laptop, since it came equipped with CL11 1600-MHz memory, I likewise wanted to stick with CL11 CAS Latency speed, instead of going for memory with a faster (lower) CL rating. Some CL9 memory cards have faster specifications, but I really think that most people will not notice 2-nanoseconds of extra latency. So I ordered this CL11 1600-MHz memory because I wanted to exactly match the specifications of my laptop's original 8-GB memory card to ensure compatibility since using mismatched memory can cause system instability. And this memory has been working flawlessly in my laptop!
In real-world applications benchmarks, there is barely any difference between using CL11 memory and using some fancier CL9 memory, and the unnoticeable speed difference is not worth paying extra money for more-expensive models of CL9 or faster memory. With most applications, if you compare CL7, CL9, and CL11 application benchmarks, the differences mostly amount to 2% to 4% differences in benchmark timings. Along with the CL listing, another important memory performance indicator is bandwidth, and this Crucial memory's DDR3 1600MHz has a very good maximum bandwidth of 12800MB/s. But what does this mean in real-world performance terms? Relatively little. As long as you have enough memory to hold the applications that you are running without paging, RAM speed is only very rarely a performance bottleneck. Even with quad-core CPUs, the bottleneck is more likely still going to be the CPU . The reason for this is that the CPU's branch prediction algorithms are so accurate that, in the vast majority of circumstances, the data is already in the cache when the CPU needs it. So direct calls to RAM are quite rare. The branch predictor is like the CPU's personal assistant; it guesses what piece of information the boss needs next and makes sure it is already on his desk by the time he needs it. Occasionally, the assistant will get it wrong and the boss will have to forage around and find the information himself. In CPU terms, "foraging around" means retrieving the information from RAM, or (worst case scenario) disk, while if it is "on the boss' desk", that is equivalent to it being in the CPU's cache. And if your computer is equipped with an SSD using Intel's "Smart Response Technology" or if your computer uses SSDs instead of hard disks, it may retrieve the data from the speedy SSD instead of reading from a slower hard disk.
So the days are long-gone when purchasing high-end expensive RAM actually makes a tangible difference to your computer's performance. As long as it meets the basic specifications that your chipset requires, there is not much to be gained by paying more. Some performance gains are possible from buying better RAM, but these days, most tests tend to show that such performance gains are minimal... far, far lower than you will get from adding more RAM (not necessarily faster RAM, just *more* RAM) or a faster CPU. This was not always the case. When the Pentium IV first came out thirteen years ago, it used a new type of RAM that had, at the time, very high bandwidth, but also very high latency. AMD's Athlon used traditional RAM with lower bandwidth and lower latency. Some types of applications (e.g. video and audio conversion) were very sensitive to bandwidth, but less sensitive to latency. These types of applications showed significant performance gains with the Pentium IV. Other applications (typically games and office applications) were more sensitive to latency and favored the Athlon.
Overall, this Crucial memory is a great buy! Don't overspend on memory just because a brand or model of memory touts better specifications. If you are a hardcore computer gamer with a $4000 gaming laptop, you may opt for faster high-end memory to complement your top-of-the-line CPU and graphics. But most people should focus far more on how compatible that memory's specifications are for your system because the differences between CL ratings are negligible if you are considering CL rating differences of 2 or 3, while using memory that is not correctly matched or compatible with your computer can cause a variety of problems.
After I removed the original Samsung 8-GB memory from my Y410P laptop and added these two Crucial SODIMM cards, I reran the Windows Experience Index benchmark and got the same WEI "Memory operations per second" score of 8.1 that I had with the Samsung memory. The WEI "Processor: Calculations per second" also remained unchanged at 8.1. This was not surprising considering that both the original Samsung memory and this Crucial memory have the same specifications.
I also purchased a single 8GB card of this same Crucial memory to upgrade my HP Chromebox, which comes equipped with only 2GB in its single memory slot. There is a lot of misleading information on the Internet stating the maximum memory that you can use in the HP Chromebox is 4GB. But that is incorrect since the HP Chromebox can fully use 8GB of memory. After I upgraded my HP Chromebox, the Memory Monitor app on its Chrome OS displayed the memory capacity as 7.9GB. 2GB of memory is sufficient for a Chromebook/Chromebox if you are just browsing with a few tabs open. But if you want to open up lots of tabs and run lots of apps, or if you plan to install Linux or Windows on your Chromebook/Chromebox, then adding more memory will help with performance.
Note that Crucial has two identical 16-GB 2x8GB kits with identical specifications, with each memory product having two different part numbers: CT2K8G3S160BM/CT2C8G3S160BM [[ASIN:B008LTBJFW Crucial 16GB Kit (8GBx2) DDR3 1600 MHz (PC3-12800) CL11 SODIMM 204-Pin 1.35V/1.5V Mac Memory CT2K8G3S160BM]] , and CT2KIT102464BF160B/CT2CP102464BF160B [[ASIN:B007B5S52C Crucial 16GB Kit (8GBx2) DDR3 1600 MT/s (PC3-12800) CL11 SODIMM 204-Pin 1.35V/1.5V Notebook Memory CT2KIT102464BF160B]]. CT2K8G3S160BM/CT2C8G3S160BM and CT2KIT102464BF160B/CT2CP102464BF160B are exactly the same memory cards, with the only difference being that the CT2K8G3S160BM/CT2C8G3S160BM product is packaged for Macs with the words "Mac Compatible" on the package. But all four of these part numbers are totally interchangeable because they contain identical memory cards. So if you determine that this is the right memory for your computer, just get whichever of these four Crucial part numbers is cheapest :-) I purchased the CT2K8G3S160BM/CT2C8G3S160BM on Amazon because it was $30 cheaper than the CT2KIT102464BF160B/CT2CP102464BF160B product listing at the time (of course, prices can vary each day). Both of these products are dual-voltage and can work in either 1.35V PC3L/DDR3L or 1.50V PC3/DDR3 memory slots. Both products are Mac-compatible, but they are also not Mac-specific or PC-specific, and they work equally well with PCs, Macs, and Chromebook/Chromebox.
If my review helped you to make an informed buying decision, please click the [Yes] button below. If not, please offer suggestions for how I can improve this review. If you have questions, please ask.
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Wonderful, Absolutely wonderful, 13", Mid 2012 Intel i5 Macbook Pro
By
Nick McPherson
on
January 2, 2015
Verified Purchase
I'm loving this upgrade!!! I have a 13", Mid 2012 Intel i5 Macbook Pro 500 GB Toshiba HDD (Soon to be Samsung 850 Pro 256 GB SSD). Apple says this laptop can only handle a maximum of 8GB of ram (or memory), mine is currently recognizing and running smoothly with 16GB at the full 1600 MHz.
I was a little iffy when purchasing this where it's above apple's rated max, but I think it's just apple trying to get you to buy an equipped (and more expensive) macbook pro, even though mine is 2 years old. I also am in the process of upgrading to a Samsung 850 Pro SSD (Solid State Drive, Flash memory for whom don't know). This model Macbook pro does run on DDR3 ram, however DDR3L is a lower voltage ram, meaning less heat, and saves energy (every bit counts when it comes to saving as your mac is about to die). I don't know if my mac can run it at the lower voltage, but this ram and other DDR3L ram is backwards compatible.
I've heard stories of this ram not working for some after a couple days, so play it save and don't throw out, sell, or give away your original ram (at least right away) incase it does fry. I will update this review after 1 month, 6 month, and 1 year's use to keep you updated even though most likely few people will be buying this ram this time next year (or maybe everyone will be)
I highly recommend upgrading your ram and HDD to a SSD to give your aging computer some or maybe even more then of the it once had.
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OK for Apple Mac mini
By
Sumo do
on
October 9, 2014
Style: DDR3 1600MHz
Size: 16GB Kit (2 x 8GB)
Verified Purchase
I purchased the HX316LS9IBK2/16 kit. I can confirm it works in the Apple Mac mini 2012 2.6 GHz i7 Quad Core model and the 2011 2.0GHz i7 Quad Core Server. It is recognised on both as 1600MHz. I ran a few benchmark runs on Nova Bench and it brings up approx results of 8500 MB/s on the 2.6GHz and around 7400 MB/s on the 2.0GHz. I compared this to running 16GB of Corsair Vengeance (CMSX16GX3M2A1600C10) on the same Macs. Unfortunately Nova Bench results flucuate around 300-400 MB/s on results with each test so it is hard to give an exact result (unless I repeat it 50 times and take and average) but I would have to say that the Vengeance only beat the Hyper X 2 times over 8 goes. Generally the Vengeance was 100 MB/s or so slightly lower than the Hyper X. They are very rough guesstimates though. Having said that I have used my Vengeance chips for over two years now and they have been bullet proof. I would recommend either, but just wanted to try the Hyper X because it is over 2 years down the track in technology.
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A night and day difference.
By
d
on
October 31, 2016
Verified Purchase
Worked great on a mid-2012 MacBook Pro. My computer had started getting sluggish and studdering due to running basic programs like Word. It turns out it is pretty easy to max out the 4GB that comes with it. I took about 10 minutes to install after watching a video on how to do it. It is very simple. The difference is immediate and continuous! I also ordered an SSD to replace, and I'm sure that will make a big difference, but honestly if I knew that it would make it seem brand new again, I probably would have saved the extra money and only did this. As I write this, my memory monitor says 3.80GB used...before this update, that means I'm close to being maxed out just by being on Amazon using Safari with Word and some other programs installed. Now, this isn't an issue, and high volume pages (like Amazon) and programs pop up instantaneously. I love it!
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![Corsair Vengeance 16GB (2x8GB) DDR3 1600 MHz (PC3 12800) Laptop Memory 1.5V]({"https://images-na.ssl-images-amazon.com/images/I/51%2BEHiBPGzL._SX425_.jpg":[274,425],"https://images-na.ssl-images-amazon.com/images/I/51%2BEHiBPGzL._SX355_.jpg":[229,355],"https://images-na.ssl-images-amazon.com/images/I/51%2BEHiBPGzL._SX450_.jpg":[290,450],"https://images-na.ssl-images-amazon.com/images/I/51%2BEHiBPGzL._SX466_.jpg":[300,466],"https://images-na.ssl-images-amazon.com/images/I/51%2BEHiBPGzL.jpg":[322,500]})
