From mboxrd@z Thu Jan 1 00:00:00 1970 From: erik quanstrom Date: Wed, 3 Aug 2011 09:16:00 -0400 To: 9fans@9fans.net Message-ID: <49ccb17004fa073b227cafb46a8fc9db@brasstown.quanstro.net> In-Reply-To: <201108030755.28900.dexen.devries@gmail.com> References: <8a5ab6631b9767218fac1c48e0a2ccd2@brasstown.quanstro.net> <201108030755.28900.dexen.devries@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Subject: Re: [9fans] cheep ssds Topicbox-Message-UUID: 0b91dd00-ead7-11e9-9d60-3106f5b1d025 > On Wednesday 03 of August 2011 05:53:51 erik quanstrom wrote: > > i just got a 40gb intel ssd for building up a new file > > server. i really wasn't expecting 275 out of a theoretical > > 300mb/s. maybe i forgot how to count and it's actually > > 27.5. :-) > > ah, marketing. megabits per second, rather than megabytes. > > nb., SATAII isn't twenty times faster than PATA, just two times. 3GBit minus > 8/10 encoding. i would think it takes some concerted mental effort to rain on a 275mb/s parade. 91% efficiency is near staturation. :-). i remember when sata 3.0gbps was overkill. that was 2009. i think the speed ratio of 2:1 is not correct. first, you must be assuming udma 133. i have never seen a udma 133 target. http://www.newegg.com/Product/ProductList.aspx?Submit=Property&Subcategory=14&Description=&Type=&N=100007603&IsNodeId=1&srchInDesc=&MinPrice=&MaxPrice=&PropertyCodeValue=359%3A7788 the fastest udma device i can find is udma 100. this is not 100mhz, it's 100mb/s. where as 3.0gb sata is 3.0gb/s / 10 bits/byte = 300mb/s. that's 3x, not 2x. (both are in decimal, as you can calculate from the udma cycle time of 40ns, double-pumped). and of course sata 6.0gb is 6x faster than pata. that being said, pata is dead as fried chicken. it's worse in every way than sata. (no hot plug, shared channels, terrible connector, etc, that master vs slave nonsense.) i could go on. i'd use sata over pata even if it cost me a bit of speed. - erik