iM 4,1-14,4 What upgrades are available and recommended 2009 iMac 10,1

[Raditude]

I have a 21.5inch, Late 2009 iMac
Core 2 Duo 3.06GHz
4GB 1067MHz DDR3 RAM
Nvidia GeForce 9400, 256MB GPU

I've been searching the forums, and I'm a bit confused as to what upgrades are possible.
I've been told that my iMac can take a Xeon processor, but I can't find anything definitive about that on the forum. What's the best Xeon that would be possible without flashing the bios, without overloading the power supply, or overheating the system? Basically I'm looking for a plug-n-play option.

I've heard conflicting info on whether this Mac can take 8 or 16GB of RAM. How much can it take, and what's the highest clock speed accepted?

The hard drive in it runs obnoxiously slow and is throwing SMART errors, as I found out when trying to update it to Sonoma. I would like to put an SSD in. Are there any recommendations for which SSDs would be compatible? This would only be a secondary computer, and doesn't need much storage. A 256GB or 512GB would be fine.

Also, the ethernet port is borked. It doesn't recognize when I connect a cable. I've done sound troubleshooting... with multiple cables, and connecting to known good devices. I've tried an external USB ethernet port, and the system didn't recognize the device (The device might have been too new, as I was on Yosemite at the time). Any ideas for how to fix it?

 

[Amethyst1]

I've been told that my iMac can take a Xeon processor, but I can't find anything definitive about that on the forum.

No idea about Xeons, but Core 2 Quads don’t work so the fastest known compatible CPU is the Core 2 Duo E8600 (3.33 GHz).

How much can it take, and what's the highest clock speed accepted?

8 GB 1067 MHz DDR3 as two 4 GB modules.

Are there any recommendations for which SSDs would be compatible?

The MCP79 southbridge is picky in that some SATA III (6 Gbps) SSDs only negotiate SATA I speed (1.5 Gbps) rather than SATA II (3 Gbps). So the SSD you pick must be able to reliably step down to 1.5 Gbps — or negotiate 3 Gbps.

 

[theMarble]

No idea about Xeons, but Core 2 Quads don’t work so the fastest known compatible CPU is the Core 2 Duo E8600 (3.33 GHz).

In theory, any Yorkfield LGA775 Xeon should work, as their specs are extremely similar, but come in quad-core variants.

The fastest chip you may be able to get working is the Xeon L3360, which is a low-voltage quad-core 2.83GHz chip. You could try out the X3380, which is a 95W 3.17GHz chip, but I don't know if the 21.5" can handle that much thermal output.

By that same theory, the Wolfdale-6M-based Core 2 Quad Q8200S/Q8400S/Q9400S/Q9505S and the Wolfdale Q9550S may have a chance at working as well. They are all extremely similar in all specifications/requirements to the E8600.

8 GB 1067 MHz DDR3 as two 4 GB modules.

The 21.5" '09 can handle 16GB with two matching 8GB 1066 MHz sticks. I say matching as the MCPx9 chipsets are very picky about higher density memory.

 

[Amethyst1]

By that same theory, the Wolfdale-6M-based Core 2 Quad Q8200S/Q8400S/Q9400S/Q9505S and the Wolfdale Q9550S may have a chance at working as well.

This thread has shown that quad-cores either don’t work at all, or only as dual-cores.

The 21.5" '09 can handle 16GB with two matching 8GB 1066 MHz sticks.

Good to know, that was news to me.

 

[theMarble]

This thread has shown that quad-cores either don’t work at all, or only as dual-cores.

Never knew that! So it seems then that the C2D E8600 is probably the fastest CPU you can put in a 21.5" 2009.

 

[Amethyst1]

Never knew that! So it seems then that the C2D E8600 is probably the fastest CPU you can put in a 21.5" 2009.

…or possibly the E8700, if you can find one. (The X5270 doesn’t play ball.)

 

[DeltaMac]

hmm... the OP has a Late 2009, 21.5-inch iMac (iMac10,1), which has 4 RAM slots (not 2), so max RAM is 4x4GB = 16GB. That doesn't necessarily make upgrades easy. As mentioned above that first-gen 21.5-inch is definitely picky about RAM. Crucial brand will usually be your good choice for that.