CPU vs RAM: Best bang for your buck ?

[Daniel-san]

Hi Guys,

I was wondering where I could get the most out of my money. I'm currently piecing my hardware for a new build.

let's say I have a 16TB setup.

going with the consent that I have 300$ to spend, that 16GB or Ram cost 100$ and a intel 1155 cost 100$

would it benefit me to throw an extra 100$ to double my ram to 32GB ?
or would it be better to get a faster 200$ CPU ?



my FreeNas will be connect via iSCSS to my ESX host, where a VM will be converting video (StreamToMe) for my various iDevices, GF's included.

My gut tells me more ram, but this forum says for CIFS shares, the faster clocked CPU the beter.

since I can't configure these "streams servers" to work with FTP and forced to use CIFs shares, where should I drop my extra hundo ?

 

[survive]

Hi Daniel-san,

What CPU are you starting with? I would imagine a simple i3-2100 would be fine for your application.

You are looking at a Supermicro board, right? Keep in mind those require unbuffered ECC RAM.

-Will

 

[Daniel-san]

I was thinking a regular desktop motherboard, an asus in the 100$ range as well.

should I be aiming for a supermicro board ?

 

[survive]

Hi Daniel-san,

I'm sorry, I got you confused with another user with a similar question.

Personally, if I was building a fresh filer I'd have a tough time not going with a Supermicro board.

If you are considering going with something like that keep in mind that they use ECC unbuffered RAM.

-Will

 

[Daniel-san]

if I go with actually real server hardware, the motherboard is 2x the cost, the Ram is 4x the cost. not to mention the Xeon CPU.

with the additional cost, what am I really gaining ?

I current have an old AMD 939 with 2GB of DDR1 running Windows HomeServer. I'll be reusing the 16TB I have in there; but as far as reliability goes, the thing never gave me issues. sure it's slow and I have outgrown what solutions it can provide me but this is why I'm doing this refresh.

I don't think I'll have enough simultaneous users on the box where I would need ECC Ram.
I see it more as want than a need.

 

[survive]

Hi Daniel-san,

I think your pricing is a bit off.....at least in newegg dollars.

The cheapest Supermicro 1155 board lists for $160
An Intel i3-2100 will cost you ~$100
16GB of Kingston RAM will run you ~$130

So I would think you are really only paying maybe $60 more for "server grade" hardware. Once you get your consumer-grade rig built I won't be surprised to see you back here asking about the poor network performance...you will then be advised to spend the $30 for a proper Intel "CT" NIC. So in the end you are really only out $30...

You are also pretty much guaranteed that the Supermicro board will support a SAS\SATA HBA (like a M1015 or BR10i) without issue.

Take a look at this thread: http://forums.freenas.org/showthread.php?7591-Best-Recommendations-for-FreeNAS-with-Apple-Xserve <--Post #4

-Will

 

[bfishernc]

Sorry for jumping in - Along these lines... RAM vs SSD ZIL?

I currently have 8GB RAM, but mobo can handle more. I assume I'm better off investing in RAM than I am 2 SSDs for a ZIL? (I'm trying to run a few VMs off of this freenas box)

Or is this apples/oranges and I need both :)

 

[jgreco]

You theoretically don't need ZIL until you're pushing a lot of traffic. ZIL is primarily used for sync writes such as metadata updates. RAM helps speed along read ops, and L2ARC helps a bit more. What's your traffic like? Are your VM's designed for a virtual environment? Are they doing lots of writes? You need to characterize your traffic in order to make intelligent decisions about where to spend cash.

 

[bfishernc]

Sorry for lack of detail. Running NFS, home environment (2 hosts, about 25 VMs, 10 of which are View desktops). Currently using local storage (mix of disks and SSD) for most VMs, but would like to take advantage of vMotion, DRS, etc so would like to use my FreeNAS box to hold as many of my VMs as possible. If I put more than 3-4 VMs (virtual servers, mostly idle (ie DNS, AD, AV (vShield)) on my current setup, I start seeing latency alerts in vCenter and responsiveness gets real sluggish.

When I look at the charts in FreeNAS, I always have about .5Mbits of Rx traffic, and when a VM is active, that jumps to 10-20M RX. TX is usually nil unless I'm moving a big file off and I'll see anywhere from 10-80M. If a VM is busy, TX will go to 20-30. My "max" values (copying big iso) appears to be about 50M RX and 100 TX.

I've been reading like crazy, and everything I see points to ZIL being very important for my usage.

I've basically boiled it down to 2 scenarios:
1) Try adding 2 SSDs in mirror for my ZIL. I understand I don't need much, but to get SATAIII, looks like 64GB is about the smallest I can find (seems like a waste to buy 2x64GB when I only need about 10seconds worth).

2) Add 2 larger SSDs in a mirrored (or 3 smaller in ZFS1) pool and use them as my VM datastore and use the spinning disks for files.

If I use scenario 1, I get the most capacity. If I use Scenario 2, I will likely have the best performance for the VMs that are on that datastore.

 

[jgreco]

You sound like you've got a handle on it. I'll just toss in that storage on SSD's is pleasantly fast, not as fast as SSD's for local datastores, but more responsive than disks especially when busy.