US$189 AKiTiO Thunder2 PCIe Box (16Gbps-TB2)

[jacobsson]

@Dschijn

Thanks man!

[mzinz]

Hi all,

I've read through the two Akitio threads, but I haven't been able to answer this question:

Is it possible to use the Akitio with a low profile (mini) GPU *without* any modding/splicing/etc?

I know that the max output is 25W... I'm wondering if there are any mid-range/decent GPUs that will fit which only require that much power?

If not, is there a clean/simple solution that gets decent performance?

Thanks in advance - sorry if these questions have been answered before!

[Dschijn]

Why low profile? Do you already own such a card? What do you want to achive? Gaming or more monitors? OSX or Windows?

There are cards with a TDP below 20W, but that cards are:

- old

- slow

A clean setup with a extra powered GPU should be the GTX 750 Ti (which doesn't work in OSX, yet). Models like the ZOTAC GTX 750 Ti OC or the Gigabyte GTX 750 Ti OC. These cards are 19cm long and the AKiTiO can handle cards (if you remove the case fan) with a length less than 20cm.

The thing is the power… The AKiTiO will provide just 25W and these cards need about 60W (TDP). This power could be provided by the additional 6Pin, which these OC cards have.

To get the power to the card you could use sth. like the Phobya External PSU 230V to 4Pin Molex 90W and than use an adapter to 6Pin…

[arclord]

Hi all,

I've read through the two Akitio threads, but I haven't been able to answer this question:

Is it possible to use the Akitio with a low profile (mini) GPU *without* any modding/splicing/etc?

I know that the max output is 25W... I'm wondering if there are any mid-range/decent GPUs that will fit which only require that much power?

If not, is there a clean/simple solution that gets decent performance?

Thanks in advance - sorry if these questions have been answered before!

I think this is the fastest GPU that fits the 25W power requirement:

http://www.geforce.com/hardware/desktop-gpus/geforce-gt-730/specifications

The GT 730 (Kelper core) with GDDR5 is the one to get. However, it is a mid to low end card.

[linh1987]

Hi Arclord, can I ask how long is the included TB cable? probably 0.5m?

[Dschijn]

yes 0.5m is the cable that ships with the AKiTiO!

[Dschijn]

Can anyone explain if is it necessary to cut some lines of the riser to prevent damaging the circuit board of the enclosure? I read there might be problems with using two PSUs (AKiTiO + ATX PSU).

Or just use the ATX PSU without powering the AKiTiO directly and rely on the power the riser is giving it?

[entzoe]

Can anyone explain if is it necessary to cut some lines of the riser to prevent damaging the circuit board of the enclosure? I read there might be problems with using two PSUs (AKiTiO + ATX PSU).

Or just use the ATX PSU without powering the AKiTiO directly and rely on the power the riser is giving it?

Hi @Dschijn , I asked this to Jim on his implementation here http://forum.techinferno.com/diy-e-gpu-projects/7205-us%24225-akitio-thunder2-pcie-box-36.html#post106674

Basically, he did cut the AkiTio power supply cable and matted it to a MOLEX. So basically from PSU, he powered his AkiTio's board, and the powered riser.

I will be receiving my new powered riser today and test this. If I still get a freezing issue or kernel panic, I might just settle with Sonnet III-D.

[jacobsson]

The board power is for the ThunderBolt chip as well as the support circuitry (clocks, etc) for the PCIe bus. As mentioned previously, any diodes in this power circuitry will prevent current back-flow and some components may not receive proper power. Or put another way: yes, the PCIe riser power is sufficient for the slot, just not a guarantee that the other circuits get proper power.

-JimJ

Sorry for coming late into the discussion, I guess you've already tested powering the board with riser only, and it gave you instability? My plan is change the 5.5/2.5mm input jack for a high current one, such as the PJ080, then route my power to the board, x16 connector and GPU (three splits).

I was hoping that the x16 connector would allow back-current so I could skip the 'board split'.

[euqlaog]

I just confirmed that the combination of molex-to-barrel-plug-adapter + molex powered riser (two yellow 12V wires + two black ground + capacitor) was stable and passed 3DMark11 test. My previous mention about system crash here must have been using two PSUs (AKiTiO + ATX) with a powered riser.

[JimJ740]

Thanks! Did you do any research on this and picked this one by any special reason? Did you cut any lines of the riser to prevend powering the AKiTiO?

I prefer the flexible printed circuits (FPC) to insulation displacement connectors and ribbon cable. I wanted to take advantage of PCIe x4, use FPC, and have power - this model fit the bill. Additionally the fact that it came with two sets of FPC, one 10cm and one 20cm let me try to run the shortest possible cables. I ended up using the 20cm set.

I did not cut any lines - and it is not that I am trying to prevent back-powering, it is that I am specifically trying NOT to RELY on back powering, since I do not have access to the schematics nor the time/desire to reverse engineer all this.

-JimJ

[JimJ740]

There are direct power tracks from the x16 slot to the x4 slot powering the Thunderbolt daughter board. x4 slot limits the power to 25W when feeding power normally via AKiTiO's 60W power adapter.

What I am a little concerned is that when using both the DC jack power and a powered riser, my system immediately shut down when began to run 3DMark11 test. I don't remember if I used molex-to-barrel-plug-adapter or AKiTiO's adapter, but won't try that again and there are some other posts here that warned the same. You said that "using multiple power supplies carries the risk of ground loops that I wanted to avoid." Is it safe to use one power source (ATX PSU) even though power is feeded from two source points on the board as you have done?

And as you have some EE background, can you comment something about this I found by googling?

"If you are testing two points in a circuit and there is a (big) capacitor between those points you may hear a quick beep and then quiet. That's because the voltage the meter is applying to the circuit is charging up the capacitor and during that time the meter 'thinks' its continuous (essentially)"

This is what happened when I did a continuity test between near DC jack and x16 slot 12V points without 4pin black/yellow cable. The short beep sound can be heard again, when switching black and red probes.

Disclaimer: I cannot see what you are doing, nor do I know what your continuity tester is. If you touch the two probes of your continuity tester together - does it give a continuous beep?

If so, then in fact you proved that there is NOT a direct power track between the tested points and in fact there is a capacitor in the circuit.

-JimJ

[JimJ740]

Sorry for coming late into the discussion, I guess you've already tested powering the board with riser only, and it gave you instability? My plan is change the 5.5/2.5mm input jack for a high current one, such as the PJ080, then route my power to the board, x16 connector and GPU (three splits).

I was hoping that the x16 connector would allow back-current so I could skip the 'board split'.

I NEVER tested powering the Akitio board from the PCIe riser. It may in fact work. My assertion is that without knowing the actual circuit, it is far more conservative from a safety and stability standpoint NOT to do so. Obviously what we are discussing here is not covered by any form of warranty or guarantees, so the amount of risk you want to assume is entirely up to the individual.

I do NOT contend that my method is guaranteed in any way, the best possible, or will work for everyone. Rather I just wanted to illustrate the method that an engineer (me) used to create a successful implementation using an AMD board, and to point out POTENTIAL but UNCONFIRMED risks associated with:

1) drawing more amperage than designed for from the power input,

2) powering the Akitio logic board from the PCIe riser, or

3) assuming that all the power connectors on a graphic card are shared and that if there is not enough power available on one connector the board will make up for it by drawing more form an alternate connector.

4) Ground loops between multiple power supplies

The consequences of the risks listed may range from very minor to very serious... you may have an unstable system, fry a board, burn your house down, or have a perfectly working system - and without having a full understanding of the circuits it is very hard to say what the relative probabilities are.

Sorry for the mini-lecture. To sum it up: when you modify the wiring of something you plug into the wall, most engineers will tell you to be as careful as possible.

[euqlaog]

Disclaimer: I cannot see what you are doing, nor do I know what your continuity tester is. If you touch the two probes of your continuity tester together - does it give a continuous beep?

If so, then in fact you proved that there is NOT a direct power track between the tested points and in fact there is a capacitor in the circuit.

-JimJ

I tested the continuity with a small multimeter (UT120A). Touching probes together gives continuous beep. Yes, there is no direct connection between those points, but from the x4 slot (has been already proved on this thread that it is electrically and physically x4) to the x16 there is. Thanks!

[jacobsson]

I NEVER tested powering the Akitio board from the PCIe riser. It may in fact work. My assertion is that without knowing the actual circuit, it is far more conservative from a safety and stability standpoint NOT to do so. Obviously what we are discussing here is not covered by any form of warranty or guarantees, so the amount of risk you want to assume is entirely up to the individual.

I do NOT contend that my method is guaranteed in any way, the best possible, or will work for everyone. Rather I just wanted to illustrate the method that an engineer (me) used to create a successful implementation using an AMD board, and to point out POTENTIAL but UNCONFIRMED risks associated with:

1) drawing more amperage than designed for from the power input,

2) powering the Akitio logic board from the PCIe riser, or

3) assuming that all the power connectors on a graphic card are shared and that if there is not enough power available on one connector the board will make up for it by drawing more form an alternate connector.

4) Ground loops between multiple power supplies

The consequences of the risks listed may range from very minor to very serious... you may have an unstable system, fry a board, burn your house down, or have a perfectly working system - and without having a full understanding of the circuits it is very hard to say what the relative probabilities are.

Sorry for the mini-lecture. To sum it up: when you modify the wiring of something you plug into the wall, most engineers will tell you to be as careful as possible.

Jesus, I just wanted to know if the board could be back powered by the riser or if there were any diodes ruining the fun for us (my thundertek PX board works like this).

I'm an engineer too and I understand the risks when elaborating with power. No disrespect intended.

[jacobsson]

I tested the continuity with a small multimeter (UT120A). Touching probes together gives continuous beep. Yes, there is no direct connection between those points, but from the x4 slot (has been already proved on this thread that it is electrically and physically x4) to the x16 there is. Thanks!

Thanks buddy, let's hope that it can be properly powered from the x16 slot, that would make me happy

[JimJ740]

Jesus, I just wanted to know if the board could be back powered by the riser or if there were any diodes ruining the fun for us (my thundertek PX board works like this).

I'm an engineer too and I understand the risks when elaborating with power. No disrespect intended.

The name is Jim, not Jesus .

Absolutely no disrespect taken, and the elaborate post was not directed specifically at you... my only real goal is information exchange on an interesting hobby project of mine. I am trying to make it clear that we are operating with incomplete knowledge - as well as to be clear about what we know as fact vs theory.

-Jim

[jacobsson]

@JimJ740

Good because I really didn't mean to, it's important to share as much information as possible.

In the EXP GDC V6 thread there has been incidents where people been shorting out stuff due to reverse polarity so I really see what you're saying.

I made my order for the thunder2 box today and I have to wait till the 7th for shipping and then some x days for delivery

[Dschijn]

I should be able to start testing latest on monday. But I am now more confused than before ^^

Fingers crossed it will be fine

[entzoe]

I tested the continuity with a small multimeter (UT120A). Touching probes together gives continuous beep. Yes, there is no direct connection between those points, but from the x4 slot (has been already proved on this thread that it is electrically and physically x4) to the x16 there is. Thanks!

Got a different riser today. Powered the board with the barrel/molex and riser from PSU. It worked......but then OS froze/kernel panic after 35mins of steam game in OS X.

Maybe I will just stay with Sonnet III-D.

?

[euqlaog]

@entzoe: It might be that the Nvidia web driver is not fully compatible with the hardware (AKiTiO & eGPU) you are using on the OSX side. You may track down the reason from the system console log what caused the kernel panic. I got one faulty riser from ebay, but luckily had some extra ones that worked. There are so many variables. I haven't done long period testing with my setup on OSX, can only say that EVGA GTX780 6GB is stable on Windows without/with the riser.

[entzoe]

Here's the kernel panic......

[jacobsson]

I should be able to start testing latest on monday. But I am now more confused than before ^^

Fingers crossed it will be fine

Yeah there is a lot of confusion right now =) Hopefully we can find out if a powered riser can do the job (w/o the AC-adapter) for powering both daughter board and x16 slot.

If that works that would mean that we don't need two power sources for the enclosure, which mean we will have one common ground = stability.

[ReaverM1]

Thanks much appreciated

[Dschijn]

My AKiTiO arrived today. Will try to do some testing in the evening (in 8h) with my GTX 670. More hardware testing will be possible on Monday.