[SOLVED] Which RAM for i7 9700k?

[bamxyuri]

Hello, I plan on buying an i7 9700k CPU and build a gaming PC with it. But I don't understand which RAM to buy and if a specific RAM has to be on the list of the motherboard or not.
If I buy for example 2x8gb Corsair Vengeance LPX 3200mhz will it work with an i7 9700k on a MSI Z390 MPG Gaming pro carbon or not? So basically, I don't understand what RAM support is, when talking about the CPU and what overclocking means. If I buy 3200mhz RAM can I test if it works and if not, can I just let it run at 2666mhz? What happens if I enable XMP, will the RAM run automatically at 3200mhz?

 

[DrummerManSpike]

You don't have to get one on the motherboard's supported list, that's just specific RAM that they've actually tested on it. The ones listed and anything similar will work just fine.

Pretty much most RAM will "work" with most CPU's, the main compatibility issue to make sure of is the physical form factor of the RAM. Most modern motherboards - including yours - are built for DDR4 RAM, which is currently the most common, so you'll be fine there.

XMP is basically an automatic overclocking tool for your RAM, which comes with pre-tested presets for the clock speed, latency, etc.. This is highly recommended if you aren't proficient with overclocking individual RAM settings.

A 3200MHz rated RAM can work at 2666MHz, however... there's no reason to do this. You're just slowing down its performance needlessly. The 9700k can handle it no problem. Make sure to enable XMP after installing the new RAM though, otherwise your motherboard will probably default it to around 2133MHz (could be higher or lower).

The Vengeance LPX line is actually a solid choice, and usually comes at great prices. Depending on your budget, I'd recommend getting a pair with a CAS latency of 14. 15 is okay if you wanna save some money, but 16 is probably the slowest I'd go for.

 

[bamxyuri]

You don't have to get one on the motherboard's supported list, that's just specific RAM that they've actually tested on it. The ones listed and anything similar will work just fine.

Pretty much most RAM will "work" with most CPU's, the main compatibility issue to make sure of is the physical form factor of the RAM. Most modern motherboards - including yours - are built for DDR4 RAM, which is currently the most common, so you'll be fine there.

XMP is basically an automatic overclocking tool for your RAM, which comes with pre-tested presets for the clock speed, latency, etc.. This is highly recommended if you aren't proficient with overclocking individual RAM settings.

A 3200MHz rated RAM can work at 2666MHz, however... there's no reason to do this. You're just slowing down its performance needlessly. The 9700k can handle it no problem. Make sure to enable XMP after installing the new RAM though, otherwise your motherboard will probably default it to around 2133MHz (could be higher or lower).

The Vengeance LPX line is actually a solid choice, and usually comes at great prices. Depending on your budget, I'd recommend getting a pair with a CAS latency of 14. 15 is okay if you wanna save some money, but 16 is probably the slowest I'd go for.

OK, so I will probably buy 2x8gb 3200mhz RAM. But I still have a question. If I use the XMP do I need to plug in the additional 4pin connector for the CPU on the motherboard (Z390 gaming pro carbon)? Because It needs at least the 8pin connector and I read in another forum that for extreme overclocking or XMP or something like that I might need to connect the additional 4pin.
Also, on the PSU which I want to buy ( semi-modular Corsair TX750m) there is no additional 4pin. There are only two 8pin connections for GPU and four 6pins for peripherals and SATA. And the fixed cable has only 8pin for CPU.
I used the MPG Z390 Gaming pro carbon for my last PC in the manual it says I should connect the CPU PWR2 to the PSU, too.

 

[Shektron]

OK, so I will probably buy 2x8gb 3200mhz RAM. But I still have a question. If I use the XMP do I need to plug in the additional 4pin connector for the CPU on the motherboard (Z390 gaming pro carbon)? Because It needs at least the 8pin connector and I read in another forum that for extreme overclocking or XMP or something like that I might need to connect the additional 4pin.
Also, on the PSU which I want to buy ( semi-modular Corsair TX750m) there is no additional 4pin. There are only two 8pin connections for GPU and four 6pins for peripherals and SATA. And the fixed cable has only 8pin for CPU.
I used the MPG Z390 Gaming pro carbon for my last PC in the manual it says I should connect the CPU PWR2 to the PSU, too.

Whether you need to or not can only really be determined by trying XMP without plugging in the additional connector, and seeing if everything works fine. If not, you plug in the additional connector. And you can use the 8-pin as a 4-pin as well, they usually either can be split into 4+4 or you can just match the correct 4 pins and connect those, and let the remaining 4 stay attached but not connected to anything.

Basically, 8-pin can act as 4+4 pin as well, same as with PCI-E connectors, which usually come as 8-pin connectors that can be split into a 6+2 configuration as some GPU's have 6-pin connectors if they don't need too much power.

 

[DrummerManSpike]

I would recommend the Corsair RM750 (2019 version). It's a similar price, fully modular, and comes with an additional 8-pin (4+4) CPU cable. It's a very solid unit that I'm actually using for my own first build, absolutely no issues so far.

At the same time though, test out the new RAM before buying the new PSU. You may end up not needing it.