Where is everyone buying their Low TDP CPUs from?

[wisem2540]

I have been looking for a 45w (or so) CPU....like the I7-4790T but I cant seem to find any on newegg...same for the "L" Xeon E3 and E5

[tdallen]

I don't really see the point of using a low TDP chip for unRAID - they're the right solution for laptops and other implementations where heat dissipation is an issue, but why throttle a well cooled server with a clock limited CPU?  Idle power consumption is about the same for the regular chips and the low TDP chips.

[wisem2540]

My current server uses a 1045T 125w chip and runs anywhere from 100-160w.  I figure its costing me about 20-25 dollars a month to run

[JonathanM]

My current server uses a 1045T 125w chip and runs anywhere from 100-160w.  I figure its costing me about 20-25 dollars a month to run

This.

Idle power consumption is about the same for the regular chips and the low TDP chips.

The newer chips are much more efficient overall, they turn off circuits they don't need internally. The TDP value is maximum power at full load, and has nothing to do with day to day power usage.

 

Let me paint a picture with words. You have a transcoding job that requires X amount of maths to be completed. The low TDP version of the chip will slow itself down so as not to exceed its power dissipation rating, and take much longer to do the same amount of maths. The total electricity to do the job is about the same for the CPU, possibly even totalling more overall power with the low TDP chip because the rest of the machine is waiting on the job to complete. The normal chip has finished the job in a shorter time, and allowed the drives to spin down, thus actually saving power.

 

[wisem2540]

My current server uses a 1045T 125w chip and runs anywhere from 100-160w.  I figure its costing me about 20-25 dollars a month to run

This.

Idle power consumption is about the same for the regular chips and the low TDP chips.

The newer chips are much more efficient overall, they turn off circuits they don't need internally. The TDP value is maximum power at full load, and has nothing to do with day to day power usage.

 

Let me paint a picture with words. You have a transcoding job that requires X amount of maths to be completed. The low TDP version of the chip will slow itself down so as not to exceed its power dissipation rating, and take much longer to do the same amount of maths. The total electricity to do the job is about the same for the CPU, possibly even totalling more overall power with the low TDP chip because the rest of the machine is waiting on the job to complete. The normal chip has finished the job in a shorter time, and allowed the drives to spin down, thus actually saving power.

 

Ok I am with you.  I can forget low TDP chips.  If I go with a standard 80w Core I7, I will still save money over my 1045T right?  Plus I would go from about a 4000 passmark to about a 10,000 passmark and give my server some breathing room.  I am not always starved for CPU, but my 8GB of RAM is being pushed to the max with crashplan running.  So a rebuild is in order.

 

The other option I have is leaving the build as is, and just buying 16GB of Ram.  But if there is enough savings to be had over time from the power savings, id like to do that

[JonathanM]

If I go with a standard 80w Core I7, I will still save money over my 1045T right?  Plus I would go from about a 4000 passmark to about a 10,000 passmark and give my server some breathing room.

If you keep the exact same workload, you will definitely save power. However, it's been my experience that the more capable the machine is, the more you want to push it, so I don't know how MUCH you will save. You are getting over double the CPU benchmark, and a lower TDP as well, so yes, it should use less power.

[IamSpartacus]

I'm a big proponent of the new Xeon D chips.  I have used the 1540 (8-core, 45w) and I just bought two 1537's (8-core, 35w) and a 1518 (4 core, 35w) to build out my new vSAN cluster.

 

For the poster saying you don't see the point of low TDP chips...I'll tell you a very good reason.  Noise!  The noise produced by my servers is the main reason why I went with the Xeon D's.  My servers sit right next to my desk in an open door office right off my living room.  For those of you lucky enough to have basements where you can stow your servers away this is not a concern of yours I know.  But for those of us who live in apartments or in houses where we have to keep our gear right in our living spaces, low TDP chips will help reduce noise by reducing the need for higher speed fans.

[tdallen]

I'll tell you a very good reason.  Noise!

Good point, and directly related to cooling.  There's a perception, though, that lower TDP chips will cost less to operate and in my experience there's no real truth to that if you're asking them to do the same amount of work as a regular CPU.  I definitely like the look of the new Xeon Ds - that's a lot of processing for the money.

 

To the OP - if you are coming from an AMD Phenom II X6 1045T you are going to find that modern Intel chips are a LOT more power efficient.

[IamSpartacus]

I'll tell you a very good reason.  Noise!

Good point, and directly related to cooling.  There's a perception, though, that lower TDP chips will cost less to operate and in my experience there's no real truth to that if you're asking them to do the same amount of work as a regular CPU.  I definitely like the look of the new Xeon Ds - that's a lot of processing for the money.

 

To the OP - if you are coming from an AMD Phenom II X6 1045T you are going to find that modern Intel chips are a LOT more power efficient.

 

To be honest, it's the idle power where you don't see much of a difference in the chips, especially the newer ones because Haswell on does a really good job of spinning down unused cores.  But if you are comparing the power usage of say a 45w chip at full load to a 125w chip at full load you will see a difference.  The real question is how often is your CPU being stressed and is it therefore going to have any noticeable impact on your electric bill.  For a lot of the people that answer is no.