iMac 8,1 2008 8gb ram upgrade

I have seen the same symtoms. I even ordered two of the exact crucial modules specified by Broken_Mouse (who had no problems). With 8GB, the machine runs in a very unstable state, lots of spinning Rainbow Balls. Machine just feels very, very sluggish. CPU usage is reported only in part by activity monitor, but the system definitely 'feels' busy, even on menial tasks. It should be noted that the system did register and use the RAM, showing the free space and used space totalling 8GB.

I am wondering if it's related to shared video RAM. The scrolling action in Safari, for instance, was very blocky and not smooth. Dragging windows around in the Finder was also delayed and slow. Memtest passed initial tests, although I did not have time to complete the tests completely. Locking the RAM took a very long time.

I removed one chip and went to 6GB, and the machine feels and operates normally. I would NOT suggest upgrading to 8GB, but 6GB does seem to work fine.

Running 10.7.5, Core2Duo 2.8GHz, 24".

Bought 2x4 GB Crucial new for cheap. With the intention of upgrading to 6GB and selling the othe 4GB with an existing 2GB of Crucial as a 6GB kit... Read this thread a long time ago and just had to try 8GB in my iMac 24" (Early 2008).. Running absolutely flawlessly for 2 days solid. Running Logic Pro X effortlessly...

Mac is running smoother, no beachballs, no page outs & no crashes, Faster start ups my apps are flying, I'm literally clicking and they are open. Have read it may be registering the RAM but only using 6GB, My only thing with that is why if it did that would it make some systems unstable if only actually using the 6GB?

I also thought maybe because I have the 3.06?

Using Crucial CT51264AC800 x2 4GB which is the same spec as my old 2x 2GB Crucial all (CL6 - Non-ECC - Unbuffered - 1.8v)

What are the apps to test the RAM fully?

Running 10.8.5 Core2Duo 3.06GHZ, 24"

Hi Nevel88

I would ask you if your upgraded Ram Imac is working fine too.

Thanks

Riccardo

After upgrading Snow Leopard to Mavericks, 8GB started causing me trouble. A lot of trouble. High CPU, dragging like a dog, all the snappiness gone through the window. Firstly I thought that it was my SSD causing me all this trouble (have Samsung 840). So I made a copy of the drive to the external disk with Clonezilla and booted from external drive. No change. I then lowered my memory back to 4GB/6GB and all was great and snappy again, like nothing ever happened. Just to prove the point that 8GB works well with the SL, I restored SL from my backup disk by using clonezilla, and presto, 8GB worked like a charm.

No idea what's causing this behaviour, but I can confirm that in my case with the latest version of the OS, 8G of RAM on old 2008 iMac doesn't work well. It doesn't crash the system, but it slows it down so much that it becomes unusable. 6GB works well and as fast if not faster than 4GB. 8GB of RAM only works for me when I run Snow Leopard.

I understand Apple recommend only 4GB for this machine ... though it is well known that 6GB works well. Once you go above that you have to be asking for trouble. Didn't you research it?

Sure I did. Many people had success with 8GB on early 2008 iMac, hence my attempt to try it. In my case, it actually works fine on SL but not necessarily on the newest OS.

Hi Broken_Mouse,

I have an Apple iMac 2.8GHz Intel Core 2 Duo (24-inch - 800MHz) MB325LL/A Desktop/PC running OSX Mavericks currently running off 2GB Ram and it runs slowwwww. I want to upgrade to 8GB ram and was wondering if your machine is still operating efficientl on 8gb? Also, what kind of ram did you buy?

Please let me know when you get a chance. Thanks!

It worked ok was as fast as **** responce wise , then, I just noticed downloads were slower and cpu would often max out I didn't try it with SL just ML and Mavericks.. I am now using 6GB and tbh it fly's, It really depends what you are doing. But you will definately not regret the extra ecspecially going from 2GB, even if you just get another 2 GB stick it's 100% more.. I used Crucial two 4GB now a 2 & 4 module.

Many users make the mistake of buying what as known as Cut Rate or Cheap Ram. Many of the older users who are very knowledgeable prefer to use TOP OF THE LINE RAM when it comes to Mac Comuters. Because it avoids problems in the long run. Many of us prefer to used matched sets of Ram to also avoid issues. Here are 2 of the Top of the Line in Ram.

http://www.crucial.com

as well

http://eshop.macsales.com/shop/apple/memory/

Im new to macs

these are my specs

what is the highest i can upgrade my ram?

and where can i buy it from?

i can install them my self. just want to buy the parts

If you click on the more info button, you'll get a complete window of your entire Mac system.

Copy/paste all of this info editing out your Mac's serial number and paste the info into another reply here.

We need to know the Mac model ID number.

Correct and reliable Mac RAM can be purchased from online Mac RAM sources Crucial memory or OWC (macsales.com).

See Donald Morgan's links directly above your post.

Model Name: iMac

Model Identifier: iMac8,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2.4 GHz

Number Of Processors: 1

Total Number Of Cores: 2

L2 Cache: 6 MB

Memory: 1 GB

Bus Speed: 1.07 GHz

Boot ROM Version: IM81.00C1.B00

SMC Version (system): 1.29f1

You can install a total of 6 GBs of RAM, max..

I, strongly, advise purchasing and installing the complete 6 GBs of RAM.

OWC (macsales.com) has the complete 6 GB RAM kit here.

http://eshop.macsales.com/item/Other%20World%20Computing/6400DDR2S6GP/

Good Luck!

this is my problem as well. I am facing to updateing RAM, for first instant Appla recommended 4 gig ( 2+2...) but I read this conversation here, now I am confused, might I ( need I?) more RAM, hence the 6 Giga, what many good fellow recommended?

2+6 at OWC cost about $130, any other cheap option for 2+2 could be only $53

http://http://www.amazon.com/Kingston-Modules-Macbook-KTA-MB800K2-4GR/dp/B001RMG 62Q/ref=sr_1_2?ie=UTF8&qid=1400802508&sr=8-2&keywords=imac+memory+2gb

Please allowe me asking more: what about installation? How could I make it myself? could I? 2+2 cost $ 60 by

Fry,s Electric , they asking $ 35 labor.

2007 and 2008 year model iMacs can take a total of 6 GBs of RAM.

One 2 GB module and One 4 GB module.

Macs are VERY, VERY picky abou the RAM specs they need.

You CANNOT purchase RAM for Macs from any local computer or electronics store or from any ole' online retailer, such as Amazon.

DON'T EVEN TRY!!!,

Correct, compatible and reliable Mac RAM can be purchased from online Mac RAM sources Crucial memory or OWC (macsales.com).

OWC ( macsales.com) has the 6 GB RAM kit you need.

http://eshop.macsales.com/item/Other%20World%20Computing/6400DDR2S6GP/

RAM is, completely, user installable and, relatively, easy to install.

http://eshop.macsales.com/installvideos/imac_mid_2007_mem_h/

Good Luck!