Slotting 'Old' CPUs into 'New' motherboards

[Caius Filimon]

Hello guys,

 

I was wondering if it is a general rule, or mainly true in a few exceptional cases, that older CPUs do not work if slotted into newer motherboards.

 

I do not have access to my PC atm to see what motherboard it has, but I know it has an i5 4690k slotted in. On PC Parts Picker if I try to slot that CPU into a newer Micro ITX motherboard it says there may be some compatibility issues:

• 'Some Intel H81 chipset motherboards may need a BIOS update prior to using Haswell Refresh CPUs. Upgrading the BIOS may require a different CPU that is supported by older BIOS revisions.'

The motherboard I'm trying to couple the i5 is with the Asus H81M-PLUS Motherboard.

I don't suppose there's any other way to upgrade the BIOS other than with some other CPU?

 

Any help would be hugely appreciated.

[Radium_Angel]

As long as the socket is the same then the general rule stands, but never put an old CPU in a new board (or vice versa) if the sockets don't match

[Gameking002]

and usually it is a good thing if the chipset was specifically made for that architecture the CPU is running

[Caius Filimon]

3 minutes ago, Radium_Angel said:

As long as the socket is the same then the general rule stands, but never put an old CPU in a new board (or vice versa) if the sockets don't match

So it would be a risky business for me to try to buy a new micro itx motherboard for a cpu the likes of the i5 4690k?

 

If they are not compatible, would there be anything I could do about it?

2 minutes ago, Gameking002 said:

and usually it is a good thing if the chipset was specifically made for that architecture the CPU is running

Does it simply make the CPU more stable/capable to be underbolted/overvolted/overclocked or does it genuinely hurt the performance of the CPU in most cases?

[Oshino Shinobu]

H81 motherboards are older than the 4690K, so it's actually putting a new CPU into an old motherboard. 

 

There isn't really a general rule, as it changes depending on the chipset and CPU. If the socket is different, it won't work at all. If the socket is the same, then there may need to be a BIOS update for it to work, or it may not work at all regardless of BIOS. There isn't an overwhelming majority case for how things work when dealing with new boards with the same socket, so general rules don't really exist for that. For example, the current 8th gen Intel CPUs require a 300 series chipset motherboard, despite using the same socket as 100 and 200 series chipsets (LGA 1151)

 

In this case, The board would need an updated BIOS to support the newer CPU. It may already have the BIOS, or it may not, no way to tell without booting it up and looking. Some boards can update the BIOS without a CPU, but that board cannot. Only way to update it is with a currently compatible CPU. 

 

If you're buying a new board, go for one that's using one of the chipsets released along with Haswell Refresh CPUs. For a 4690K, you should really be going for a Z97 chipset board, but H97 will work if you're not fussed about overclocking (or SLI and some of the other Z97 exclusive features)

[WoodenMarker]

2 minutes ago, Oshino Shinobu said:

In this case, The board would need an updated BIOS to support the newer CPU. It may already have the BIOS, or it may not, no way to tell without booting it up and looking.

If you're buying the board, it's a good idea to ask the seller if the bios is updated. You need revision 2001 or newer for the 4690k. The CPU support list can be found on the motherboard website. https://www.asus.com/us/Motherboards/H81MPLUS/HelpDesk_CPU/

[Oshino Shinobu]

Just now, WoodenMarker said:

If you're buying the board, it's a good idea to ask the seller if the bios is updated. You need revision 2001 or newer for the 4690k. The CPU support list can be found on the motherboard website. https://www.asus.com/us/Motherboards/H81MPLUS/HelpDesk_CPU/

Also worth noting that some shops will update the BIOS for you if you ask nicely. Would advise just buying a 90 series chipset board though.

[Gameking002]

1 minute ago, Caius Filimon said:

So it would be a risky business for me to try to buy a new micro itx motherboard for a cpu the likes of the i5 4690k?

no, not if they are made to be compatible, though it will be an older motherboard probably

1 minute ago, Caius Filimon said:

If they are not compatible, would there be anything I could do about it?

probably not, maybe looking for certain bios, but that is not guaranteed to fix it

2 minutes ago, Caius Filimon said:

Does it simply make the CPU more stable/capable to be underbolted/overvolted/overclocked or does it genuinely hurt the performance of the CPU in most cases?

that can greatly depend on which combination you make of CPU/Chipset. it should not affect performance greatly, but it can be designed for different power delivery for different architectures, therefore not really being capable of OverClock/VoltageControl to the degree that is generally found on compatible CPUs and their respecting Chipsets

[Caius Filimon]

Thank you all for your fast and informative responses. I very much appreciate it.

 

Could someone please link me to some guide outlining which motherboard type fits which generation CPUs? Thank you.

[Caius Filimon]

And another crucial question for myself: would most motherboards, or at least the CPU compatible Z97/H97 accept a 1070Ti Mini? 

[Gameking002]

3 minutes ago, Caius Filimon said:

And another crucial question for myself: would most motherboards, or at least the CPU compatible Z97/H97 accept a 1070Ti Mini? 

yeah, GPU (PCI-e) does not rely upon CPU/Chipset, it merely depends upon the lowest PCI-e revision that your motherboard/GPU supports, and that only determines the speed that the card will run at. so as long as it has a compatible slot (which im sure it will have), yes, it will definitely be able to run that new of a GPU.

[Caius Filimon]

Just now, Gameking002 said:

yeah, GPU (PCI-e) does not rely upon CPU/Chipset, it merely depends upon the lowest PCI-e revision that your motherboard/GPU has, and that only determines the speed that the card will run at. so as long as it has a compatible slot (which im sure it will have), yes, it will definitely be able to run that new of a GPU.

Thank you very much! So depending on the motherboard, the GPU might be bottlenecked? Or do you mean that it will be restricted in how much further it can go from stock speeds?

[Gameking002]

Just now, Caius Filimon said:

Thank you very much! So depending on the motherboard, the GPU might be bottlenecked? Or do you mean that it will be restricted in how much further it can go from stock speeds?

the PCI-e gen1/gen2/gen3 are speed standards that PCI-e slots support, and if the cards supports said speed too (if not it will use lower because of backwards-compatibility), it means it can use the full potential of the speed the slot has to offer, and this only affects the speed of communication between the GPU and CPU. so the slot does not directly affect the clockspeed of the card, it merely affects the data the GPU can get from other components (which it will then have to process). so if data for procession cant be fed fast enough to your GPU, yes it shall be lacking in speed because it doesnt have enough data to saturate all its cores. and this can be seen as a bottleneck, but it will be a bottleneck originating from the rest of the system, and not the GPU.

[WoodenMarker]

23 minutes ago, Caius Filimon said:

Thank you very much! So depending on the motherboard, the GPU might be bottlenecked? Or do you mean that it will be restricted in how much further it can go from stock speeds?

Here are some pcie scaling benchmarks with a 1080: https://www.techpowerup.com/reviews/NVIDIA/GeForce_GTX_1080_PCI_Express_Scaling/24.html

If you're using a graphics card that utilizes more or less bandwidth, there's more or less of a benefit to bandwidth.

[Caius Filimon]

14 minutes ago, Gameking002 said:

the PCI-e gen1/gen2/gen3 are speed standards that PCI-e slots support, and if the cards supports said speed too (if not it will use lower because of backwards-compatibility), it means it can use the full potential of the speed the slot has to offer, and this only affects the speed of communication between the GPU and CPU. so the slot does not directly affect the clockspeed of the card, it merely affects the data the GPU can get from other components (which it will then have to process). so if data for procession cant be fed fast enough to your GPU, yes it shall be lacking in speed because it doesnt have enough data to saturate all its cores. and this can be seen as a bottleneck, but it will be a bottleneck originating from the rest of the system, and not the GPU.

Thank you for the explanation.

 

I am now at a complete loss in terms of what would be a good idea to look for. Whatever I search on the British amazon website I cannot find a Z97 micro atx motherboard, and most all other types of chipset micro atx motherboards on pc parts picker are not compatible.

[WoodenMarker]

3 minutes ago, Caius Filimon said:

Thank you for the explanation.

I am now at a complete loss in terms of what would be a good idea to look for. Whatever I search on the British amazon website I cannot find a Z97 micro atx motherboard, and most all other types of chipset micro atx motherboards on pc parts picker are not compatible.

r/HardwareswapUK should have a good number of boards floating around and you can probably ask for a bios update if you're getting an older chipset.

[asand1]

I dont know Haswell. Could someone please just tell him what LGA socket he needs and quit with the chipset numbers?