Re: [casper] SFP+ board reliability
Hi Rich, So far we haven't had any trouble with the SFP+ boards (8 total) in our vegas machine. I guess they've been powered up continuously and in use for around a year now. We were concerned about how warm the PHY chips run so I spent a little time looking into it. The datasheet says: For typical applications, the VSC8486 can be operated in an ambient temperature environment of +80 degrees C with no airflow and without a heatsink. It also states that the maximum specification for case temperature is 85C (95C in one case). I used our IR viewer and noted that the case temperature reached ~60degC on the bench and a little less on the ones in the rack. I should note that the datasheet was for the VSC8486 so I had to assume that the thermal specs are similar for the VSC8488, which is the actual chip on the SFP+ mezz boards. Given all of that info, we elected not to put heat sinks on ours. Hope this helps, Jason At 12:25 PM 12/6/2013, Rich Lacasse wrote: Hi All, We've had a failure of an SFP+ board for no apparent reason. We've not put any work into trouble shooting except to isolate the failure to the SFP+ board, as opposed to a ROACH2 or optical transceiver. Has anyone else experienced failures? The two PHY chips on these boards run very warm whether or not they are transmitting data. We are considering putting heatsinks on them. Has anyone else been down this road already? Any other advice? Thanks, Rich
Re: [casper] SFP+ board reliability
hi jason, thanks for the temperature data and measurements. were your temperature measurements in the standard roach2 enclosure? i think the VEGAS SFP+ PHY's are mounted differently and have different cooling than the standard roach2 enclosure. best wishes, dan On Fri, Dec 6, 2013 at 9:53 AM, Jason Ray j...@nrao.edu wrote: Hi Rich, So far we haven't had any trouble with the SFP+ boards (8 total) in our vegas machine. I guess they've been powered up continuously and in use for around a year now. We were concerned about how warm the PHY chips run so I spent a little time looking into it. The datasheet says: For typical applications, the VSC8486 can be operated in an ambient temperature environment of +80 degrees C with no airflow and without a heatsink. It also states that the maximum specification for case temperature is 85C (95C in one case). I used our IR viewer and noted that the case temperature reached ~60degC on the bench and a little less on the ones in the rack. I should note that the datasheet was for the VSC8486 so I had to assume that the thermal specs are similar for the VSC8488, which is the actual chip on the SFP+ mezz boards. Given all of that info, we elected not to put heat sinks on ours. Hope this helps, Jason At 12:25 PM 12/6/2013, Rich Lacasse wrote: Hi All, We've had a failure of an SFP+ board for no apparent reason. We've not put any work into trouble shooting except to isolate the failure to the SFP+ board, as opposed to a ROACH2 or optical transceiver. Has anyone else experienced failures? The two PHY chips on these boards run very warm whether or not they are transmitting data. We are considering putting heatsinks on them. Has anyone else been down this road already? Any other advice? Thanks, Rich
Re: [casper] SFP+ board reliability
Hi Dan, One measurement was made with a bare roach2 board just sitting on the bench in the lab. The other was made with the vertical mount roach2 arrangement that we use in the vegas rack. Thanks, Jason At 01:19 PM 12/6/2013, Dan Werthimer wrote: hi jason, thanks for the temperature data and measurements. were your temperature measurements in the standard roach2 enclosure? i think the VEGAS SFP+ PHY's are mounted differently and have different cooling than the standard roach2 enclosure. best wishes, dan On Fri, Dec 6, 2013 at 9:53 AM, Jason Ray mailto:j...@nrao.eduj...@nrao.edu wrote: Hi Rich, So far we haven't had any trouble with the SFP+ boards (8 total) in our vegas machine. I guess they've been powered up continuously and in use for around a year now. We were concerned about how warm the PHY chips run so I spent a little time looking into it. The datasheet says: For typical applications, the VSC8486 can be operated in an ambient temperature environment of +80 degrees C with no airflow and without a heatsink. It also states that the maximum specification for case temperature is 85C (95C in one case). I used our IR viewer and noted that the case temperature reached ~60degC on the bench and a little less on the ones in the rack. I should note that the datasheet was for the VSC8486 so I had to assume that the thermal specs are similar for the VSC8488, which is the actual chip on the SFP+ mezz boards. Given all of that info, we elected not to put heat sinks on ours. Hope this helps, Jason At 12:25 PM 12/6/2013, Rich Lacasse wrote: Hi All, We've had a failure of an SFP+ board for no apparent reason. We've not put any work into trouble shooting except to isolate the failure to the SFP+ board, as opposed to a ROACH2 or optical transceiver. Has anyone else experienced failures? The two PHY chips on these boards run very warm whether or not they are transmitting data. We are considering putting heatsinks on them. Has anyone else been down this road already? Any other advice? Thanks, Rich
Re: [casper] SFP+ board reliability
I've had no failures I can prove are related in anyway to the operating temperature. Even so and mainly just because I didn't like how warm the parts felt and had no way to access nor control the Vitesse parts temperature monitoring functions I've added these heatsinks to my ~20 SFP+ boards 15.2 x 15.x 6.35 mm heat sink black anodize w/ adhesive thermal tape http://www.aavid.com/products/bga/375424b00034g 40 units @ @2.994 On Fri, 6 Dec 2013, Rich Lacasse wrote: Date: Fri, 06 Dec 2013 12:25:17 -0500 From: Rich Lacasse rlaca...@nrao.edu To: casper@lists.berkeley.edu Subject: [casper] SFP+ board reliability Hi All, We've had a failure of an SFP+ board for no apparent reason. We've not put any work into trouble shooting except to isolate the failure to the SFP+ board, as opposed to a ROACH2 or optical transceiver. Has anyone else experienced failures? The two PHY chips on these boards run very warm whether or not they are transmitting data. We are considering putting heatsinks on them. Has anyone else been down this road already? Any other advice? Thanks, Rich
