Vertminer Crash

[Lexomatico]

I start Vertminer with my 3 R9 290x gpu and after some time it crash....
My system:
asus Z87 Xpower, 8gb ddr3 ram, i3 CPU & 3x Sapphire r9 290x with new bios

next rig

asus z87-g55, 8gb ddr3 ran, celeron cpu & 3x sapphire r9 290x with new bios

either have lepa g1600 powersupply





my miner settings:

}
]
,
"intensity" : "20",
"worksize" : "256",
"lookup-gap" : "2",
"gpu-fan" : "100",
"gpu-engine" : "1000",
"gpu-memclock" : "1500",
"gpu-powertune" : "0",
"thread-concurrency" : "24404",
"expiry" : "30",
"gpu-threads" : "1",
"scan-time" : "1"
}
 and my cgminer dose not crash......

my miner settings:
}
]
,
"intensity" : "20",
"vectors" : "1",
"worksize" : "256",
"kernel" : "scrypt",
"lookup-gap" : "2",
"thread-concurrency" : "32768",
"gpu-engine" : "1040",
"gpu-memclock" : "1500",
"gpu-memdiff" : "0",
"gpu-powertune" : "0",
"temp-cutoff" : "100",
"temp-overheat" : "99",
"temp-target" : "88",
"api-mcast-port" : "4028",
"api-port" : "4028",
"gpu-fan" : "50-100",
"failover-only" : true,
"expiry" : "28",
"gpu-threads" : "1",
"hotplug" : "5",
"log" : "5",
"no-pool-disable" : true,
"no-submit-stale" : true,
"queue" : "1",
"scan-time" : "7",
"scrypt" : true,
"temp-hysteresis" : "3",
"shares" : "0",
"kernel-path" : "/usr/local/bin"
}

anyone some answers why vertminer crash??