AMD FX-8370 only using 6 of 8 cores?

[jrlp]

Screenshot of CPU-Z: http://gyazo.com/032f86289a1a5a014d2a84dfeb0584d1

I just installed my new Fx-8370 today. After booting back up, I opened up CPU-z and Speccy to check temps and such. Both programs updated the name of my processor, but both say it's only 6 cores.

It also shows it as underclocked as you can see. I'm not sure if there are any settings i need to change or what. The processor I upgraded from was a FX-6100, which was 6 core and 3.3 ghz

 

[slyu9213]

What motherboard are you using? These are my guesses.

Windows or the BIOS setting has set the 8370 as a 6-Core
You need an BIOS update
Your motherboard does not support the CPU officially so it is clocked different with only 6-Cores.

More info will help

 

[photonboy]

1) Open Task Manager (CTRL-ALT-DEL) and observe the number of threads for the CPU section. If you see only one you need to change to show all graphs at top or right-clicking graph etc (depends on version of Windows).

If you see EIGHT then it's fine. If you see SIX it may be a problem with the BIOS settings as you can change the number there.

2) BIOS - You can boot (DEL key) into the BIOS on startup then check to see if "all cores" are selected. Not sure what the wording is exactly but if you see 6 change it to 8.

If the BIOS show 8 but Task Manager shows only 6 then it's likely some weird glitch in Windows itself but let's take it one step at a time.

3) If the BIOS has a new version then apply it, however I doubt that's the issue since an unsupported CPU shouldn't even let the PC start.

 

[jrlp]

What motherboard are you using? These are my guesses.

Windows or the BIOS setting has set the 8370 as a 6-Core
You need an BIOS update
Your motherboard does not support the CPU officially so it is clocked different with only 6-Cores.

More info will help

Motherboard is a Gigabyte GA-78LMT-S2. I've never updated my BIOS before so how would I go about doing that? I also looked at Task Manager and it says the max clock speed is 3.3ghz, which was the same for my old fx-6100. So all the information is basically the same as it was before.

 

[photonboy]

What motherboard are you using? These are my guesses.

Windows or the BIOS setting has set the 8370 as a 6-Core
You need an BIOS update
Your motherboard does not support the CPU officially so it is clocked different with only 6-Cores.

More info will help

Motherboard is a Gigabyte GA-78LMT-S2. I've never updated my BIOS before so how would I go about doing that? I also looked at Task Manager and it says the max clock speed is 3.3ghz, which was the same for my old fx-6100. So all the information is basically the same as it was before.

1) Go back to the TM as I said and show all graphs so we can see if it shows six or eight of them.

2) If THIS is the correct motherboard then you need BIOS F5A:
http://www.gigabyte.com/products/product-page.aspx?pid=3833#ov

3) Updating BIOS: for W7 there's a utility in the support section called (@BIOS) which you install. You then download the BIOS and point to it and it should apply the update.

The motherboard MANUAL (which should be downloadable as well) should also contain exact instructions.

 

[jrlp]

I went to task manager and there are only 6 graphs. I'm on windows 8 , and I went to that gigabyte website and found a BIOS F5a download for windows 8. So I just download and run that?

 

[slyu9213]

What motherboard are you using? These are my guesses.

Windows or the BIOS setting has set the 8370 as a 6-Core
You need an BIOS update
Your motherboard does not support the CPU officially so it is clocked different with only 6-Cores.

More info will help

Motherboard is a Gigabyte GA-78LMT-S2. I've never updated my BIOS before so how would I go about doing that? I also looked at Task Manager and it says the max clock speed is 3.3ghz, which was the same for my old fx-6100. So all the information is basically the same as it was before.

2) If THIS is the correct motherboard then you need BIOS F5A:
http://www.gigabyte.com/products/product-page.aspx?pid=3833#ov

OP said GA-78LMT-S2 you linked the OP a webpage for GA-78LMT-S2P which isn't the same motherboard.

@jrlp - If your motherboard is an GA-78LMT-S2 it officially only supports 95W CPUs. Rev 1.0 and 1.1 only support two Vishera CPUs which are the FX 4300 and 6300. Rev 1.2 supports the 8320E and 8370E. The latest BIOS is F6.

The FX 8370 CPU is an 125W CPU. If you install/flash F6 BIOS for your motherboard you may be able to get the FX 8320E and 8370E working but anything higher than 95W might not work correctly (like your experience with 2 less cores and slower speeds)

DO NOT FLASH THE BIOS PROVIDED BY photonboy OR YOU MIGHT BRICK YOUR MOBO TEMPORARILY OR PERMANENTLY

 

[jrlp]

So I should get a new motherboard then? I guess that's not too bad. Out of curiosity, where did you read it only supports 95w CPUs?

 

[computertech82]

the FX-8370 is only about 15% faster than a FX-6100. The 8370 is NOT really a 8 core, since each core shares part of its resources with another core (so it's really only a 4 core cpu).
the motherboard only shows support the FX-8100. but it might work for your cpu if you have the correct bios version.
http://www.gigabyte.com/products/product-page.aspx?pid=4311#
the fx 8100 requires bios version F3.

 

[slyu9213]

So I should get a new motherboard then? I guess that's not too bad. Out of curiosity, where did you read it only supports 95w CPUs?

You can either get a new motherboard that supports the FX 8370 or get an FX 8320E/8370E. I didn't read the exact words that it only supports 95W CPUs but if you look at the CPU support list the highest CPU TDP is 95W.

http://www.gigabyte.com/products/product-page.aspx?pid=4643#bios

Additionally an FX 8-Core is indeed 8-Cores that share other resources. In general cores have their own resource but the FX series do not because of how they designed it. But just because a core does not get it's own resource does not mean it's not a core. CMT vs SMT. Additionally a Phenom II X6 was and is stronger than the Bulldozer CPUs. So a 3.3GHz Phenom would be faster than a FX 6100. But an FX 8370 is definitely faster than a Phenom II X6 so it is faster than an FX 6100.

 

[jrlp]

Thanks for helping! I'm gonna go and get a new Mobo tomorrow

 

[bmacsys]

The 8370 is NOT really a 8 core, since each core shares part of its resources with another core (so it's really only a 4 core cpu).

That is total bs. AMD cores in the CMT module design meet every requirement to be called "cores". They contain the ALUs, fetch and decode , Instruction pipeline, Interrupt handling hardware, some IO control.