How Much CPU Do I Really Need?

[fungus1487]

Hi Guys,

Am coming to the end of a hardware hunt for my freenas system which hopefully should last me :P

I have a question about the following specification.

Intel Celeron G440 1.6GHz or Intel Celeron G530T 2.0Ghz
Gigabyte GA-PH67-DS3-B3
2x 4GB DDR3 RAM 1333MHz
2x AOC-SASLP-MV8 Storage Controllers
5x 2TB Seagate Barracuda Green
5x 2TB WD Caviar Green
Powercool PSU (450w, 80plus)

This will be expanded to potentially 20 disks over the course of 24 months.

Real world usage is:

- 90% of the day dormant
- 2 users MAX
- Storing/viewing photos
- Adding dvd/bluray rips to the library
- Streaming from the HTPC
- Most access is via CIFS but streaming to the HTPC is via NFS

Will either of the processors be able to keep up (link to processors below) or should I go for something with more power?
Crucial to the build though is that I keep power consumption low and these chips have a max TDP of 35w.

http://ark.intel.com/products/58667/Intel-Celeron-Processor-G440-(1M-Cache-1_60-GHz)
http://ark.intel.com/products/53415/Intel-Celeron-Processor-G530T-(2M-Cache-2_00-GHz)

I have looked into getting a low power i3 but they are expensive at the moment.

 

[xbmcg]

The most CPU is used, when you use encryption, compression or deduplication, some for parity calculations on write.
According to your use case I would say, you almost do not need a heavy cpu, but the fsb frequency could matter
in regard of how fast your memory can be used to grab / cache / spool the datastreams between dma read / network out.

Any way, even a atom processor could probably be powerfull enough - because you have almost static data, no concurrency,
all data is already compressed (mkv, mp3,jpg...), encryption is not required, deduplication is also not necessary (makes more
sense in corporate environments for e-mail or home drive storage, where all user save the same attachment 10 times - just in case).

Because of your many spindels (drives) striping of the data will increase read performance above the performance of a single disk,
so the bottleneck will probably be your LAN-Interface / switch (and the interfaces of your other 2 devices).

 

[fungus1487]

I currently have a mini-itx mobo with built in Atom D525 running 4 2TB disks in a RAIDZ and to be fair it runs perfectly. Just was unsure if the CPU needs to scale with the hardware and number of hard drives in this situation.

Where are you obtaining the FSB frequency value for these processors? I don't see it when running over the specs?

 

[xbmcg]

the mobo spec indicates what FSB speed is used (look at the dRAM Spec).

4 x 1.5V DDR3 DIMM up to 32 GB RAM
Dual channel memory architecture
supports DDR3 2133/1866/1600/1333/1066 MHz
Supports Non-ECC-modules
Support Extreme Memory Profile (XMP) modules

The FSB frequencies can be tweaked in the BIOS according to your CPU speed and the frequency dividing settings.
Any way, it is a fast motherboard and supports very fast memory modules.

Older mobo's have specs like 667MHz, or 800MHz FSB DDR2 RAM, ...
I think, the ATOM boards have something like 800..1333MHz

Also the dual channel architecture "stripes" the RAM, so you have nearly the double performance if you use a dual channel config
(identical RAM modules paired channel wise in contrast to using just a single RAM module).

You will need more cpu, if you add more parallel users and have a higher write load, or if you use more features like compression, dedup, encryption...
Otherwise, you will probably not notice an big overhead, if you add more drives / volumes.

You can also tweak your raidz, use power of 2 for data disks + 1 parity for optimal write performance:

Raidz1:
2 data + 1 parity
4 data + 1 parity
8 data + 1 parity
...

It makes patity calculations much easier for the cpu.

 

[HAL 9000]

You can also tweak your raidz, use power of 2 for data disks + 1 parity for optimal write performance:

Why?
-----

 

[joeschmuck]

Looks like you are going to be purchasing new hardware here. Just a few comments:

1) The CPU appears to have built in graphics bu the Motherboard doesn't appear to support the built in graphics so you might want a video card as well or chose a new MB. You need a video card for the initial setup and/or troubleshooting problems.

2) You look like you want to buy an enormous amount of hardware but I would caution you to buy the minimum required to get the system running. I'd buy only one SAS card and one pool of drives.

If this system is for a home system where you primarily will use it for backups of your computers, storing video files (tons of them), photos, and streaming video, audio, then I think the CPU type should be fine. I recommend buying a large sized heat sink for the CPU vice the Box version and your CPU should remain cool and with much less noise.

I doubt deduplication will be on your list of things to have and strongly recommend against it based on what I think you want to do with your system. This is something for huge data storage for offices where people have multiple copies of the same document and it comes with a premium cost as well.

Streaming video: If you desire to transcode video, eventually you might (I say might) need to upgrade your CPU but then again, we don't have any transcoding video support for FreeNAS yet. You could add it manually but I'd wait for a plug-in. Rip your videos into the format you desire to stream. I rip into VOB for DVD and been playing around with other formats for BluRay but find something that you prefer. You don't need to rip a BluRay and retain the entire HQ video, you could convert the format to something a bit smaller that is still HQ but you can save half that space. To be honest, I rent DVD's and those are fine for most movies but an action packed thriller that I MUST see in HD, BluRay for sure but I'll save it in raw format but I'm still figuring out the format I want to keep them in. I don't need 40GB when 20GB still shows all the resolution (to my eyes).

Sorry, got a little long winded there.

-Mark

 

[tatalley10]

Anyone care to update this for today's standards

Sent from my SM-G900R4 using Tapatalk

 

[Ericloewe]

Anyone care to update this for today's standards

Sent from my SM-G900R4 using Tapatalk

Pentium and up is fine for most, i3 if you need AES-NI or transcode, Xeon E3 if you're running a small scale piracy operation video transcoding service for your family, Xeon E5 if you need more RAM.