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PatrickNSF

macrumors 6502a
Original poster
Jan 24, 2011
670
367
Just purchased a new 27" i7 395X (Late 2015) but having trouble finding RAM. Crucial (where I usually purchase) doesn't have the new iMac listed yet in their "advisor tool" and said via that they're still doing testing for compatibility (whatever that means).

Any other recommended sources other than OWC? The iMac arrives at the end of the week.
 

desmond2046

macrumors regular
Jun 2, 2015
193
431
Columbus, OH, United States
The speed of the RAM is determined by its frequency (higher the better) and the CAS Latency (lower the better), roughly speaking 1866MHz CL13 and 1600MHz CL11 are of similar speed. 1866MHz CL10/11, 2133MHz CL11 are faster options.

Regarding OWC, I think they are very much overpriced. I would not recommend at all.

If you decide to keep the stock memory, then your choice is very limited. The stock memory is 1866MHz / CL13, which is very slow. When you pair it with new RAMs, it is not guaranteed that the two will work at 1866MHz even if what you buy is labeled as 1866MHz. I heard that the crucial 1866MHz / CL13 memory and Kingston HyperX 1866MHz / CL11 memory will actually work with the stock memory at 1866MHz. G.Skill and Corsair will not! Combined with the stock memory, they will work at only 1600MHz.

Since the stock memory is very slow, I think it is actually a better idea to replace them. Generally speaking, most SO-DIMM DDR3L RAMs will work on late 2015 iMac. I suggest that you get some faster RAMs since they are not necessarily more expensive.

Trusted brands for RAMs are, but not limited to:
G.Skill Ripjaws
Kingston Hyper X
Corsair Vengeance
Crucial Ballistix

Price varies over time and resellers, I would say for 8GB, reasonable prices for 1866/CL11, 1866/CL10, and 2133/CL11 are $45, $50, $60, respectively.

Choose 1866MHz CL11/10 or 2133MHz CL11 for your iMac, you would enjoy 2%-5% overall performance gain over the stock RAM.
 

PatrickNSF

macrumors 6502a
Original poster
Jan 24, 2011
670
367
Thans for the follow-up. I ended up reading through much of the referenced thread and purchased 4 x 8GB Kingston 2133/CL11s. The delta over the 1866/CL11s was about $30 in total. Given what I spent on the iMac, seemed reasonable. I appreciate the help!
 

lasloduncan

macrumors 6502a
Mar 2, 2015
528
29
Just purchased a new 27" i7 395X (Late 2015) but having trouble finding RAM. Crucial (where I usually purchase) doesn't have the new iMac listed yet in their "advisor tool" and said via that they're still doing testing for compatibility (whatever that means).

Any other recommended sources other than OWC? The iMac arrives at the end of the week.
crucial has excellent personal telephone customer service --good thing i would have ordered the wrong stuff== normal american guy in oregon..very knowledgeable and helpful....
 

Hangs

macrumors newbie
Nov 7, 2015
24
1
Midlands UK
Sorry to be a pain but adding RAM is something new to me. This is available in the UK.

Kingston 8 GB 2133 MHz DDR3L CL11 1.35 V HyperX Impact SODIMM Memory Module - Black

HX321LS11IB2/8

Am I OK to go with this? I would be looking at 4 by 8GB modules
 

PatrickNSF

macrumors 6502a
Original poster
Jan 24, 2011
670
367
Sorry to be a pain but adding RAM is something new to me. This is available in the UK.

Kingston 8 GB 2133 MHz DDR3L CL11 1.35 V HyperX Impact SODIMM Memory Module - Black

HX321LS11IB2/8

Am I OK to go with this? I would be looking at 4 by 8GB modules
I hope so – that's what I bought. Except I bought them in the 2x8 bundles (HX321LS11IB2K2/16) as it was slightly cheaper.
 

Hangs

macrumors newbie
Nov 7, 2015
24
1
Midlands UK
I hope so – that's what I bought. Except I bought them in the 2x8 bundles (HX321LS11IB2K2/16) as it was slightly cheaper.

Thanks. I have taken a punt and purchased the above from Amazon.De. It always amazes me that Amazon on the European mainland is a lot cheaper than Amazon UK.
 

jordanz

macrumors member
May 13, 2012
91
45
I heard that the crucial 1866MHz / CL13 memory and Kingston HyperX 1866MHz / CL11 memory will actually work with the stock memory at 1866MHz. G.Skill and Corsair will not! Combined with the stock memory, they will work at only 1600MHz.

Since the stock memory is very slow, I think it is actually a better idea to replace them.
Yup - can confirm this! Got two 8GB Kingston HyperX 2133's playing nicely with the stock Apple ram atm, running at 1866mhz. Very happy with this - gives me 24GB and the option to swap in another two 8GB Kingston's later when I can afford/justify the full 32GB upgrade :)
 

stephen787

macrumors newbie
Oct 30, 2015
2
0
Missed that offer. My delivery from Germany should arrive before the IMac - I hope. Any issues with the RAM before I open the packaging?

no issues, running at 2133mhz. Geekbench's memory performance score increased by 20% , not sure if that means anything in the real world
 

dcmontgomery

macrumors member
Oct 13, 2015
57
53
The speed of the RAM is determined by its frequency (higher the better) and the CAS Latency (lower the better), roughly speaking 1866MHz CL13 and 1600MHz CL11 are of similar speed. 1866MHz CL10/11, 2133MHz CL11 are faster options.

Regarding OWC, I think they are very much overpriced. I would not recommend at all.

...

Price varies over time and resellers, I would say for 8GB, reasonable prices for 1866/CL11, 1866/CL10, and 2133/CL11 are $45, $50, $60, respectively.

You say OWC is overpriced, yet you can get 32GB of RAM in 4x8GB kits for just a few more dollars than some of the Crucial and Kingston modules. I've been using OWC memory for a decade and never had an issue with their memory kits or any of their hard drives. Reliability is worth the few extra $$$$ IMHO.
 

desmond2046

macrumors regular
Jun 2, 2015
193
431
Columbus, OH, United States
You say OWC is overpriced, yet you can get 32GB of RAM in 4x8GB kits for just a few more dollars than some of the Crucial and Kingston modules. I've been using OWC memory for a decade and never had an issue with their memory kits or any of their hard drives. Reliability is worth the few extra $$$$ IMHO.
Why do you think OWC is more reliable than Crucial/Kingston/G.Skill/Corsair? The four brands are very reputable in the PC world and have been making high-performance high-quality RAM for a long time. Crucial is also a manufacture of NAND itself. Crucial is a $20 billion business while OWC is $100 million.
 

dcmontgomery

macrumors member
Oct 13, 2015
57
53
Didn't know annual revenues had anything to do with reliability and performance. I'll take OWC memory any day since it has performed well for me on a Mac Pro for nine years and two MacBook Pros for 10 years.
 
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Buerkletucson

macrumors 6502a
Sep 12, 2015
507
298
Minnesota
OWC here and nothing but great experience......they had the RAM for the newest iMac 5K the earliest so that's what I purchased. Few $$ more but in the scope of things not a big deal IMHO.
Worked like a champ.

Probably can't go wrong with any of the big players.
 

twilexia

macrumors 6502
Oct 16, 2015
282
59
OWC here and nothing but great experience......they had the RAM for the newest iMac 5K the earliest so that's what I purchased. Few $$ more but in the scope of things not a big deal IMHO.
Worked like a champ.

Probably can't go wrong with any of the big players.

I know people are generally happy with OWC but I can't help but consider them overpriced.

http://eshop.macsales.com/shop/memory/iMac/Retina-5K2015/DDR3L

For a 16GB kit (8 GB x2) at 1867 mhz they're asking for $134. Meanwhile you can pick up a Kingston HyperX 2133 or a G.skill Ripjaw 2133 for $100. http://www.amazon.com/Kingston-2133MHz-Non-ECC-HX321C11SRK2-16/dp/B00N9PVZG6

So it's 34$ premium for not even the same speed.
 

PatrickNSF

macrumors 6502a
Original poster
Jan 24, 2011
670
367
Thanks for all the help with this. Took delivery yesterday of the iMac i7 395X 1TB SSD and installed the Kingston 32GB 2133's. Everything is working well...so far.
 

Buerkletucson

macrumors 6502a
Sep 12, 2015
507
298
Minnesota
I know people are generally happy with OWC but I can't help but consider them overpriced.

http://eshop.macsales.com/shop/memory/iMac/Retina-5K2015/DDR3L

For a 16GB kit (8 GB x2) at 1867 mhz they're asking for $134. Meanwhile you can pick up a Kingston HyperX 2133 or a G.skill Ripjaw 2133 for $100. http://www.amazon.com/Kingston-2133MHz-Non-ECC-HX321C11SRK2-16/dp/B00N9PVZG6

So it's 34$ premium for not even the same speed.

When I purchased mine nobody knew if the 2133 would work and nothing else was available (known compatible) for the late 2015 iMac except through OWC. I wanted to use my OEM memory and stay @ 1867, so the 2133 would be worthless for me.

Many more options now and of course Amazon is cheaper..........I see list price is the same.
 

anerique

macrumors newbie
Nov 23, 2015
1
0
Can I still use my 32 GB 1600 MHz DDR3
ram of my old 5k into the new I mac 5k that suport 1867 ? Will I have any hardware problem if I do this ? ...
 
Last edited:

phooi

macrumors regular
Aug 3, 2007
122
0
Purchased and installed same 16GB RAM as the OP. iMac is now running 24GB. iMac is definitely snappier than when it was running 8GB.

So far so good...
 
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