[RAM] Clock speeds

[Forest_IV]

Dear reader,

 

I have grown confusion over the past days about RAM Mhz.

 

I've read that if I have 1866 Mhz RAM, it's normal for Task manager to report 933 Mhz (Custom Desktop).

Can someone explain to me the logic of that? 

1. On my laptop I have 1600Mhz RAM and task manager reports 1600Mhz. Not 800Mhz.

2. In my internship lab, the computers have 2133Mhz RAM and task manager reports 2133Mhz. Not less.

 

Am I experiencing a configuration problem on my desktop?

[Shimejii]

its all in the Name. Double Data Rate = DDR so when a ramstick says DDR4 3600, it will report 1800 mhz usually under programs, whereas it may show up as 3600 mhz in task manager.

 

ALSO make sure your XMP profile is enabled in bios, most motherboards do not run ram at their XMP speeds by default, usually its a much lower speed, as XMP can cause issues when the ram isnt stable

[Forest_IV]

I will check whether the XMP profile is enabled in bios. Thank you. 

[minibois]

The below examples are for "1600MHz memory", but of course also apply to other speeds of memory.

 

Memory has a certain amount of MHz, which is millions of 'ticks' per second.

It can do two transfers per tick though, on the 'up' and 'down' part of the tick.

 

This means memory that runs at 800MHz, actually has 1600MT/s, which is "Millions (of) transfers per second".

Memory and motherboard manufacturers choose to display this MT/s number as the Mhz.

 

A kit of memory that is advertised as "1600MHz", is actually just 1600MT/s, which is because it's 800Mhz.

A program like CPU-Z shows off the actual true speed, 800Mhz, while your motherboard will show the MT/s as the Mhz, so 1600Mhz.

Task Manager in my experience seems to change what it shows. It always says "Mhz", but it seems to sometimes shows the actual Mhz and sometimes the MT/s.

For example, my memory is running at 1333Mhz/2666MT/s and Task manager shows 1333Mhz. But I've had it show 2666Mhz in the past.

[Forest_IV]

1 minute ago, minibois said:

The below examples are for "1600MHz memory", but of course also apply to other speeds of memory.

 

Memory has a certain amount of MHz, which is millions of 'ticks' per second.

It can do two transfers per tick though, on the 'up' and 'down' part of the tick.

 

This means memory that runs at 800MHz, actually has 1600MT/s, which is "Millions (of) transfers per second".

Memory and motherboard manufacturers choose to display this MT/s number as the Mhz.

 

A kit of memory that is advertised as "1600MHz", is actually just 1600MT/s, which is because it's 800Mhz.

A program like CPU-Z shows off the actual true speed, 800Mhz, while your motherboard will show the MT/s as the Mhz, so 1600Mhz.

Task Manager in my experience seems to change what it shows. It always says "Mhz", but it seems to sometimes shows the actual Mhz and sometimes the MT/s.

For example, my memory is running at 1333Mhz/2666MT/s and Task manager shows 1333Mhz. But I've had it show 2666Mhz in the past.

Intriguing. Great and detailed explanation. 

 

Given all of this, to sum up, first of all, I should check my XMP profile in Bios. Second of all, I should trust task manager less as it may misreport the speeds of RAM and I should instead use third-party software such as CPU-Z in order to check real information.

[Chris Pratt]

1 hour ago, Forest_IV said:

Intriguing. Great and detailed explanation. 

 

Given all of this, to sum up, first of all, I should check my XMP profile in Bios. Second of all, I should trust task manager less as it may misreport the speeds of RAM and I should instead use third-party software such as CPU-Z in order to check real information.

It's not misreporting, per se, it's just reporting different info than CPU-Z, i.e. effective vs. actual clockspeed. It's like how some apps might report storage in gigabytes (base 10) or gibibytes (base 2). Either is technically accurate. They're just different ways of reporting the same info.

[Forest_IV]

3 minutes ago, Chris Pratt said:

It's not misreporting, per se, it's just reporting different info than CPU-Z, i.e. effective vs. actual clockspeed. It's like how some apps might report storage in gigabytes (base 10) or gibibytes (base 2). Either is technically accurate. They're just different ways of reporting the same info.

Ahha, got it. I do learn a lot from you lovely people. This is extremely intriguing.

 

A few questions nonetheless...

Should I worry or not about 933Mhz being reported? 

If my XMP profile is deactivated, will activating it result in the report being 1866Mhz?

[minibois]

2 hours ago, Forest_IV said:

Intriguing. Great and detailed explanation. 

 

Given all of this, to sum up, first of all, I should check my XMP profile in Bios. Second of all, I should trust task manager less as it may misreport the speeds of RAM and I should instead use third-party software such as CPU-Z in order to check real information.

CPU-Z always reports the 'true MHz', rather than the MT/s as MHz, the motherboard/memory manufacturers report. I've seen Task Manager report either one, so I would always recommend CPU-Z to know what speed it's running at.

Just remember, whatever CPU-Z reports it as; the motherboard/memory manufacturer reports double of that.

1 hour ago, Forest_IV said:

Should I worry or not about 933Mhz being reported? 

If my XMP profile is deactivated, will activating it result in the report being 1866Mhz?

If CPU-Z (and Task Manager) report 933MHz, that means your memory is running at 1866MT/s or 1866MHz as reported by your motherboard/memory manufacturer.

So if you bought 1866MHz memory and CPU-Z or Task Manager report 933Mhz? It's all running good (although again, Task manager could report 1866MHz too).

 

So the TL;DR is:

1 hour ago, Forest_IV said:

Should I worry or not about 933Mhz being reported? 

If you have memory advertised as 1866Mhz? No.

1 hour ago, Forest_IV said:

If my XMP profile is deactivated, will activating it result in the report being 1866Mhz?

If task manager already says 933Mhz, you don't have to turn it on. If it's saying a lower number, you do have to turn it on.